The PM Runtime docs say:
Drivers in ->remove() callback should undo the runtime PM changes done
in ->probe(). Usually this means calling pm_runtime_disable(),
pm_runtime_dont_use_autosuspend() etc.
From grepping code, it's clear that many people aren't aware of the
need to call pm_runtime_dont_use_autosuspend().
When brainstorming solutions, one idea that came up was to leverage
the new-ish devm_pm_runtime_enable() function. The idea here is that:
* When the devm action is called we know that the driver is being
removed. It's the perfect time to undo the use_autosuspend.
* The code of pm_runtime_dont_use_autosuspend() already handles the
case of being called when autosuspend wasn't enabled.
Suggested-by: Laurent Pinchart <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
As talked about in commit b792e64021 ("drm: no need to check return
value of debugfs_create functions"), in many cases we can get away
with totally skipping checking the errors of debugfs functions. Let's
document that so people don't add new code that needlessly checks
these errors.
Probably this note could be added to a boatload of functions, but
that's a lot of duplication. Let's just add it to the two most
frequent ones and hope people will get the idea.
Suggested-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20220222154555.1.I26d364db7a007f8995e8f0dac978673bc8e9f5e2@changeid
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Recently we added generic "edp-panel"s probed by EDID. To support
panels in this way we look at the panel ID in the EDID and look up the
panel in a table that has power sequence timings. If we find a panel
that's not in the table we will still attempt to use it but we'll use
conservative timings. While it's likely that these conservative
timings will work for most nearly all panels, the performance of
turning the panel off and on suffers.
We'd like to be able to reliably detect the case that we're using the
hardcoded timings without relying on parsing dmesg. This allows us to
implement tests that ensure that no devices get shipped that are
relying on the conservative timings.
Let's add a new debugfs entry to panel devices. It will have one of:
* UNKNOWN - We tried to detect a panel but it wasn't in our table.
* HARDCODED - We're not using generic "edp-panel" probed by EDID.
* A panel name - This is the name of the panel from our table.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.3.I209d72bcc571e1d7d6b793db71bf15c9c0fc9292@changeid
We'd like panels to be able to add things to debugfs underneath the
connector's directory. Let's plumb it through. A panel will be able to
put things in a "panel" directory under the connector's
directory. Note that debugfs is not ABI and so it's always possible
that the location that the panel gets for its debugfs could change in
the future.
NOTE: this currently only works if you're using a modern
architecture. Specifically the plumbing relies on _both_
drm_bridge_connector and drm_panel_bridge. If you're not using one or
both of these things then things won't be plumbed through.
As a side effect of this change, drm_bridges can also get callbacks to
put stuff underneath the connector's debugfs directory. At the moment
all bridges in the chain have their debugfs_init() called with the
connector's root directory.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.2.Ib0bd5346135cbb0b63006b69b61d4c8af6484740@changeid
The ti-sn65dsi86 driver shouldn't hand-roll its own bridge
connector. It should use the normal drm_bridge_connector. Let's switch
to do that, removing all of the custom code.
NOTE: this still _doesn't_ implement DRM_BRIDGE_ATTACH_NO_CONNECTOR
support for ti-sn65dsi86 and that would still be a useful thing to do
in the future. It was attempted in the past [1] but put on the back
burner. However, unless we instantly change ti-sn65dsi86 fully from
not supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR at all to _only_
supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR then we'll still need a bit
of time when we support both. This is a better way to support the old
way where the driver hand rolls things itself.
A new notes about the implementation here:
* When using the drm_bridge_connector the connector should be created
after all the bridges, so we change the ordering a bit.
* I'm reasonably certain that we don't need to do anything to "free"
the new drm_bridge_connector. If drm_bridge_connector_init() returns
success then we know drm_connector_init() was called with the
`drm_bridge_connector_funcs`. The `drm_bridge_connector_funcs` has a
.destroy() that does all the cleanup. drm_connector_init() calls
__drm_mode_object_add() with a drm_connector_free() that will call
the .destroy().
* I'm also reasonably certain that I don't need to "undo" the
drm_bridge_attach() if drm_bridge_connector_init() fails. The
"detach" function is private and other similar code doesn't try to
undo the drm_bridge_attach() in error cases. There's also a comment
indicating the lack of balance at the top of drm_bridge_attach().
[1] https://lore.kernel.org/r/[email protected]
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.1.I3ab26b7f197cc56c874246a43e57913e9c2c1028@changeid
Add the new herobrine-r1. Note that this is pretty much a re-design
compared to herobrine-r0 so we don't attempt any dtsi to share stuff
between them.
This patch attempts to define things at 3 levels:
1. The Qcard level. Herobrine includes a Qcard PCB and the Qcard PCB
is supposed to be the same (modulo stuffing options) across
multiple boards, so trying to define what's there hopefully makes
sense. NOTE that newer "CRD" boards from Qualcomm also use
Qcard. When support for CRD3 is added hopefully it can use the
Qcard include (and perhaps we should even evaluate it using
herobrine.dtsi?)
2. The herobrine "baseboard" level. Right now most stuff is here with
the exception of things that we _know_ will be different per
board. We know that not all boards will have the same set of eMMC,
nvme, and SD. We also know that the exact pin names are likely to
be different.
3. The actual "board" level, AKA herobrine-rev1.
NOTES:
- This boots to command prompt. We're still waiting on the PWM driver.
- This assumes LTE for now. Once it's clear how WiFi-only SKUs will
work we expect some small changes.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220204140550.v4.1.I5604b7af908e8bbe709ac037a6a8a6ba8a2bfa94@changeid
Like dp_out, we should have defined edp_out in sc7280.dtsi so we don't
need to do this in the board files.
Like dp_hot_plug_det, we should define edp_hot_plug_det in
sc7280.dtsi.
We should set the default pinctrl for edp_hot_plug_det in
sc7280.dtsi. NOTE: this is _unlike_ the dp_hot_plug_det. It is
reasonable that in some boards the dedicated DP Hot Plug Detect will
not be hooked up in favor of Type C mechanisms. This is unlike eDP
where the Hot Plug Detect line (which functions as "panel ready" in
eDP) is highly likely to be used by boards.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220202132301.v3.7.Ic84bb69c45be2fccf50e3bd17b845fe20eec624c@changeid
This patch makes a few improvements to the way that sdc1 / sdc2
pinctrl is specified on sc7280:
1. There's no reason to "group" the sdc pins into one overarching node
and there's a downside: we have to replicate the hierarchy in the
board device tree files. Let's clean this up.
2. There's really not a lot of reason not to list the "pinctrl" for
sdc1 (eMMC) in the SoC dtsi file. These aren't GPIO pins and
everyone's going to specify the same pins.
3. Even though it's likely that boards will need to override pinctrl
for sdc2 (SD card) to add the card detect GPIO, we can be symmetric
and add it to the SoC dsti file.
4. Let's get rid of the word "on" from the normal config and add a
"sleep" suffix to the sleep config. This looks cleaner to me.
This is intended to be a no-op change but it could plausibly change
behavior depending on how the pinctrl code parses things. One thing to
note is that "SD card detect" is explicitly listed now as keeping its
pull enabled in sleep since we still want to detect card insertions
even if the controller is suspended (because no card is inserted). The
pinctrl framework likely did this anyway, but it's nice to see it
explicit.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220202132301.v3.4.I79baad7f52351aafb470f8b21a9fa79d7031ad6a@changeid
Recently we added generic "edp-panel"s probed by EDID. To support
panels in this way we look at the panel ID in the EDID and look up the
panel in a table that has power sequence timings. If we find a panel
that's not in the table we will still attempt to use it but we'll use
conservative timings. While it's likely that these conservative
timings will work for most nearly all panels, the performance of
turning the panel off and on suffers.
We'd like to be able to reliably detect the case that we're using the
hardcoded timings without relying on parsing dmesg. This allows us to
implement tests that ensure that no devices get shipped that are
relying on the conservative timings.
Let's add a new sysfs entry to panel devices. It will have one of:
* UNKNOWN - We tried to detect a panel but it wasn't in our table.
* HARDCODED - We're not using generic "edp-panel" probed by EDID.
* A panel name - This is the name of the panel from our table.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20220125135406.1.I62322abf81dbc1a1b72392a093be0c767da9bf51@changeid
This factors out a device tree fragment from some sc7280 device
trees. It represents the device tree bits that should be included for
"Chrome" based sc7280 boards. On these boards the bootloader (Coreboot
+ Depthcharge) configures things slightly different than the
bootloader that Qualcomm provides. The modem firmware on these boards
also works differently than on other Qulacomm products and thus the
reserved memory map needs to be adjusted.
NOTES:
- This is _not_ quite a no-op change. The "herobrine" and "idp"
fragments here were different and it looks like someone simply
forgot to update the herobrine version. This updates a few numbers
to match IDP. This will also cause the `pmk8350_pon` to be disabled
on idp/crd, which I belive is a correct change.
- At the moment this assumes LTE skus. Once it's clearer how WiFi SKUs
will work (how much of the memory map they can reclaim) we may add
an extra fragment that will rejigger one way or the other.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220125144316.v2.3.Iac012fa8d727be46448d47027a1813ea716423ce@changeid
The upcoming herobrine-r1 board is really not very similar to
herobrine-r0. Let's get rid of the "herobrine.dtsi" file and stick all
the content in the -r0 dts file directly. We'll also rename the dts so
it's obvious that it's just for -r0.
While renaming, let's actually name the file so it's obvious that
"herobrine" is both the name of the board and the name of the
"baseboard". In other words "herobrine" is an actual board but also
often used as the name of a whole class of similar boards that forked
from a design. While "herobrine-herobrine" is a bit of mouthful it
makes it more obvious which things are part of an actual board rather
than the baseboard.
NOTE: herobrine-rev0's days are likely doomed and this device tree is
likely to be deleted in the future.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20220125144316.v2.2.Id9716db8c133bcb14c9413144048f8d00ae2674f@changeid
This reverts commit cefdd52fa0.
On sc7180-trogdor class devices with 'fw_devlink=permissive' and KASAN
enabled, you'll see a Use-After-Free reported at bootup.
The root of the problem is that dwc3_qcom_of_register_core() is adding
a devm-allocated "tx-fifo-resize" property to its device tree node
using of_add_property().
The issue is that of_add_property() makes a _permanent_ addition to
the device tree that lasts until reboot. That means allocating memory
for the property using "devm" managed memory is a terrible idea since
that memory will be freed upon probe deferral or device unbinding.
Let's revert the patch since the system is still functional without
it. The fact that of_add_property() makes a permanent change is extra
fodder for those folks who were aruging that the device tree isn't
really the right way to pass information between parts of the
driver. It is an exercise left to the reader to submit a patch
re-adding the new feature in a way that makes everyone happier.
Fixes: cefdd52fa0 ("usb: dwc3: dwc3-qcom: Enable tx-fifo-resize property by default")
Cc: stable <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20211207094327.1.Ie3cde3443039342e2963262a4c3ac36dc2c08b30@changeid
Signed-off-by: Greg Kroah-Hartman <[email protected]>
When we added the support for the AUX channel in commit 13afcdd727
("drm/bridge: parade-ps8640: Add support for AUX channel") we forgot
to set "drm_dev" to avoid the warning splat at the beginning of
drm_dp_aux_register(). Since everything was working I guess I never
noticed the splat when testing against mainline. In any case, it's
easy to fix. This is basically just like commit 6cba3fe433 ("drm/dp:
Add backpointer to drm_device in drm_dp_aux") but just for the
parade-ps8640.
Fixes: 13afcdd727 ("drm/bridge: parade-ps8640: Add support for AUX channel")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Philip Chen <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206162907.1.I1f5d1eba741e4663050ec1b8e39a753f6e42e38b@changeid
If you happened to try to access `/dev/drm_dp_aux` devices provided by
the MSM DP AUX driver too early at bootup you could go boom. Let's
avoid that by only allowing AUX transfers when the controller is
powered up.
Specifically the crash that was seen (on Chrome OS 5.4 tree with
relevant backports):
Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 0 PID: 3131 Comm: fwupd Not tainted 5.4.144-16620-g28af11b73efb #1
Hardware name: Google Lazor (rev3+) with KB Backlight (DT)
Call trace:
dump_backtrace+0x0/0x14c
show_stack+0x20/0x2c
dump_stack+0xac/0x124
panic+0x150/0x390
nmi_panic+0x80/0x94
arm64_serror_panic+0x78/0x84
do_serror+0x0/0x118
do_serror+0xa4/0x118
el1_error+0xbc/0x160
dp_catalog_aux_write_data+0x1c/0x3c
dp_aux_cmd_fifo_tx+0xf0/0x1b0
dp_aux_transfer+0x1b0/0x2bc
drm_dp_dpcd_access+0x8c/0x11c
drm_dp_dpcd_read+0x64/0x10c
auxdev_read_iter+0xd4/0x1c4
I did a little bit of tracing and found that:
* We register the AUX device very early at bootup.
* Power isn't actually turned on for my system until
hpd_event_thread() -> dp_display_host_init() -> dp_power_init()
* You can see that dp_power_init() calls dp_aux_init() which is where
we start allowing AUX channel requests to go through.
In general this patch is a bit of a bandaid but at least it gets us
out of the current state where userspace acting at the wrong time can
fully crash the system.
* I think the more proper fix (which requires quite a bit more
changes) is to power stuff on while an AUX transfer is
happening. This is like the solution we did for ti-sn65dsi86. This
might be required for us to move to populating the panel via the
DP-AUX bus.
* Another fix considered was to dynamically register / unregister. I
tried that at <https://crrev.com/c/3169431/3> but it got
ugly. Currently there's a bug where the pm_runtime() state isn't
tracked properly and that causes us to just keep registering more
and more.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Link: https://lore.kernel.org/r/20211109100403.1.I4e23470d681f7efe37e2e7f1a6466e15e9bb1d72@changeid
Signed-off-by: Rob Clark <[email protected]>
In commit 510410bfc0 ("drm/msm: Implement mmap as GEM object
function") we switched to a new/cleaner method of doing things. That's
good, but we missed a little bit.
Before that commit, we used to _first_ run through the
drm_gem_mmap_obj() case where `obj->funcs->mmap()` was NULL. That meant
that we ran:
vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
...and _then_ we modified those mappings with our own. Now that
`obj->funcs->mmap()` is no longer NULL we don't run the default
code. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP
was important because we're now getting crashes on Chromebooks that
use ARC++ while logging out. Specifically a crash that looks like this
(this is on a 5.10 kernel w/ relevant backports but also seen on a
5.15 kernel):
Unable to handle kernel paging request at virtual address ffffffc008000000
Mem abort info:
ESR = 0x96000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000
[ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003,
pud=00000001002b3003, pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
[...]
CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...]
Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT)
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
pc : __arch_copy_to_user+0xc0/0x30c
lr : copyout+0xac/0x14c
[...]
Call trace:
__arch_copy_to_user+0xc0/0x30c
copy_page_to_iter+0x1a0/0x294
process_vm_rw_core+0x240/0x408
process_vm_rw+0x110/0x16c
__arm64_sys_process_vm_readv+0x30/0x3c
el0_svc_common+0xf8/0x250
do_el0_svc+0x30/0x80
el0_svc+0x10/0x1c
el0_sync_handler+0x78/0x108
el0_sync+0x184/0x1c0
Code: f8408423 f80008c3 910020c6 36100082 (b8404423)
Let's add the two flags back in.
While we're at it, the fact that we aren't running the default means
that we _don't_ need to clear out VM_PFNMAP, so remove that and save
an instruction.
NOTE: it was confirmed that VM_IO was the important flag to fix the
problem I was seeing, but adding back VM_DONTDUMP seems like a sane
thing to do so I'm doing that too.
Fixes: 510410bfc0 ("drm/msm: Implement mmap as GEM object function")
Reported-by: Stephen Boyd <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Tested-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/20211110113334.1.I1687e716adb2df746da58b508db3f25423c40b27@changeid
Signed-off-by: Rob Clark <[email protected]>
In commit 142639a52a ("drm/msm/a6xx: fix crashstate capture for
A650") we changed a6xx_get_gmu_registers() to read 3 sets of
registers. Unfortunately, we didn't change the memory allocation for
the array. That leads to a KASAN warning (this was on the chromeos-5.4
kernel, which has the problematic commit backported to it):
BUG: KASAN: slab-out-of-bounds in _a6xx_get_gmu_registers+0x144/0x430
Write of size 8 at addr ffffff80c89432b0 by task A618-worker/209
CPU: 5 PID: 209 Comm: A618-worker Tainted: G W 5.4.156-lockdep #22
Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT)
Call trace:
dump_backtrace+0x0/0x248
show_stack+0x20/0x2c
dump_stack+0x128/0x1ec
print_address_description+0x88/0x4a0
__kasan_report+0xfc/0x120
kasan_report+0x10/0x18
__asan_report_store8_noabort+0x1c/0x24
_a6xx_get_gmu_registers+0x144/0x430
a6xx_gpu_state_get+0x330/0x25d4
msm_gpu_crashstate_capture+0xa0/0x84c
recover_worker+0x328/0x838
kthread_worker_fn+0x32c/0x574
kthread+0x2dc/0x39c
ret_from_fork+0x10/0x18
Allocated by task 209:
__kasan_kmalloc+0xfc/0x1c4
kasan_kmalloc+0xc/0x14
kmem_cache_alloc_trace+0x1f0/0x2a0
a6xx_gpu_state_get+0x164/0x25d4
msm_gpu_crashstate_capture+0xa0/0x84c
recover_worker+0x328/0x838
kthread_worker_fn+0x32c/0x574
kthread+0x2dc/0x39c
ret_from_fork+0x10/0x18
Fixes: 142639a52a ("drm/msm/a6xx: fix crashstate capture for A650")
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20211103153049.1.Idfa574ccb529d17b69db3a1852e49b580132035c@changeid
Signed-off-by: Rob Clark <[email protected]>
The RTC on the pmk8350 is not useful on all boards. Some boards may
not provide backup power to the PMIC but might have another RTC on the
board that does have backup power. In this case it's better to not use
the RTC on the PMIC.
At the moment, the only boards that includes this PMIC are sc7280-idp
and sc7280-idp2. On sc7280-idp I'm not aware of any other RTCs, but
sc7280-idp2 has a Chrome OS EC on it and this is intended to provide
the RTC for the AP.
Let's do what we normally do for hardware that's not used by all
boards and set it to a default status of "disabled" and then enable it
on the boards that need it.
NOTE: for sc7280-idp it's _possible_ we might also want to add
`allow-set-time;`. That could be the subject of a future patch if it
is indeed true.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Satya Priya <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
[bjorn: Enable the RTC on the MTP as well]
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20210929153553.1.Ib44c2ac967833d7a3f51452d44d15b7b8d23c1f0@changeid
In commit e11f5bd822 ("drm: Add support for DP 1.4 Compliance edid
corruption test") the function connector_bad_edid() started assuming
that the memory for the EDID passed to it was big enough to hold
`edid[0x7e] + 1` blocks of data (1 extra for the base block). It
completely ignored the fact that the function was passed `num_blocks`
which indicated how much memory had been allocated for the EDID.
Let's fix this by adding a bounds check.
This is important for handling the case where there's an error in the
first block of the EDID. In that case we will call
connector_bad_edid() without having re-allocated memory based on
`edid[0x7e]`.
Fixes: e11f5bd822 ("drm: Add support for DP 1.4 Compliance edid corruption test")
Reported-by: Ville Syrjälä <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005192905.v2.1.Ib059f9c23c2611cb5a9d760e7d0a700c1295928d@changeid
Signed-off-by: Dave Airlie <[email protected]>
In the commit bac9c29482 ("drm/edid: Break out reading block 0 of
the EDID") I broke out reading the base block of the EDID to its own
function. Unfortunately, when I did that I messed up the handling when
drm_edid_is_zero() indicated that we had an EDID that was all 0x00 or
when we went through 4 loops and didn't get a valid EDID. Specifically
I needed to pass the broken EDID to connector_bad_edid() but now I was
passing an error-pointer.
Let's re-jigger things so we can pass the bad EDID in properly.
Fixes: bac9c29482 ("drm/edid: Break out reading block 0 of the EDID")
Reported-by: kernel test robot <[email protected]>
Reported-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20211004092100.1.Ic90a5ebd44c75db963112be167a03cc96f9fb249@changeid
Due to a simple typo (apparently I can't count. It goes 0, 1, 2 and
not 0, 2, 3) we were getting a kernel doc warning that looked like
this:
include/drm/drm_edid.h:530: warning:
Function parameter or member 'vend_chr_1' not described in 'drm_edid_encode_panel_id'
include/drm/drm_edid.h:530: warning:
Excess function parameter 'vend_chr_3' description in 'drm_edid_encode_panel_id'
Fix it.
Fixes: 7d1be0a09f ("drm/edid: Fix EDID quirk compile error on older compilers")
Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210927074104.1.Ibf22f2a0b75287a5d636c0570c11498648bf61c6@changeid
The commit 82ea7d411d ("arm64: dts: qcom: sc7180: Base dynamic CPU
power coefficients in reality") and the commit be0416a3f9 ("arm64:
dts: qcom: Add sc7180-trogdor-homestar") passed each other in the
tubes that make up the Internet. Despite the fact the patches didn't
cause a merge conflict, they need to account for each other. Do that.
Fixes: 82ea7d411d ("arm64: dts: qcom: sc7180: Base dynamic CPU power coefficients in reality")
Fixes: be0416a3f9 ("arm64: dts: qcom: Add sc7180-trogdor-homestar")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20210923081352.1.I2a2ee0ac428a63927324d65022929565aa7d8361@changeid
It's hard for someone (like me) who's not following closely to know
what the suggested best practices are for error printing in DRM
drivers. Add some hints to the header file.
In general, my understanding is that:
* When possible we should be using a `struct drm_device` for logging
and recent patches have tried to make it more possible to access a
relevant `struct drm_device` in more places.
* For most cases when we don't have a `struct drm_device`, we no
longer bother with DRM-specific wrappers on the dev_...() functions
or pr_...() functions and just encourage drivers to use the normal
functions.
* For debug-level functions where we might want filtering based on a
category we'll still have DRM-specific wrappers, but we'll only
support passing a `struct drm_device`, not a `struct
device`. Presumably most of the cases where we want the filtering
are messages that happen while the system is in a normal running
state (AKA not during probe time) and we should have a `struct
drm_device` then. If we absolutely can't get a `struct drm_device`
then these functions begrudgingly accept NULL for the `struct
drm_device` and hopefully the awkwardness of having to manually pass
NULL will keep people from doing this unless absolutely necessary.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Thomas Zimmermann <[email protected]>
Acked-by: Lyude Paul <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921082757.RFC.1.Ibd82d98145615fa55f604947dc6a696cc82e8e43@changeid
The sc7180's dynamic-power-coefficient violates the device tree bindings.
The bindings (arm/cpus.yaml) say that the units for the
dynamic-power-coefficient are supposed to be "uW/MHz/V^2". The ones for
sc7180 aren't this. Qualcomm arbitrarily picked 100 for the "little" CPUs
and then picked a number for the big CPU based on this.
At the time, there was a giant dicussion about this. Apparently Qualcomm
Engineers were instructed not to share the actual numbers here. As part
of the discussion, I pointed out [1] that these numbers shouldn't really
be secret since once a device is shipping anyone can just run a script
and produce them. This patch is the result of running the script I posted
in that discussion on sc7180-trogdor-coachz, which is currently available
for purchase by consumers.
[1] https://lore.kernel.org/r/CAD=FV=U1FP0e3_AVHpauUUZtD-5X3XCwh5aT9fH_8S_FFML2Uw@mail.gmail.com/
I ran the script four times, measuring little, big, little, big. I used
the 64-bit version of dhrystone 2.2 in my test. I got these results:
576 kHz, 596 mV, 20 mW, 88 Cx
768 kHz, 596 mV, 32 mW, 122 Cx
1017 kHz, 660 mV, 45 mW, 97 Cx
1248 kHz, 720 mV, 87 mW, 139 Cx
1324 kHz, 756 mV, 109 mW, 148 Cx
1516 kHz, 828 mV, 150 mW, 148 Cx
1612 kHz, 884 mV, 182 mW, 147 Cx
1708 kHz, 884 mV, 192 mW, 146 Cx
1804 kHz, 884 mV, 207 mW, 149 Cx
Your dynamic-power-coefficient for cpu 0: 132
825 kHz, 596 mV, 142 mW, 401 Cx
979 kHz, 628 mV, 183 mW, 427 Cx
1113 kHz, 656 mV, 224 mW, 433 Cx
1267 kHz, 688 mV, 282 mW, 449 Cx
1555 kHz, 812 mV, 475 mW, 450 Cx
1708 kHz, 828 mV, 566 mW, 478 Cx
1843 kHz, 884 mV, 692 mW, 476 Cx
1900 kHz, 884 mV, 722 mW, 482 Cx
1996 kHz, 916 mV, 814 mW, 482 Cx
2112 kHz, 916 mV, 862 mW, 483 Cx
2208 kHz, 916 mV, 962 mW, 521 Cx
2323 kHz, 940 mV, 1060 mW, 517 Cx
2400 kHz, 956 mV, 1133 mW, 518 Cx
Your dynamic-power-coefficient for cpu 6: 471
576 kHz, 596 mV, 26 mW, 103 Cx
768 kHz, 596 mV, 40 mW, 147 Cx
1017 kHz, 660 mV, 54 mW, 114 Cx
1248 kHz, 720 mV, 97 mW, 151 Cx
1324 kHz, 756 mV, 113 mW, 150 Cx
1516 kHz, 828 mV, 154 mW, 148 Cx
1612 kHz, 884 mV, 194 mW, 155 Cx
1708 kHz, 884 mV, 203 mW, 152 Cx
1804 kHz, 884 mV, 219 mW, 155 Cx
Your dynamic-power-coefficient for cpu 0: 142
825 kHz, 596 mV, 148 mW, 530 Cx
979 kHz, 628 mV, 189 mW, 475 Cx
1113 kHz, 656 mV, 230 mW, 461 Cx
1267 kHz, 688 mV, 287 mW, 466 Cx
1555 kHz, 812 mV, 469 mW, 445 Cx
1708 kHz, 828 mV, 567 mW, 480 Cx
1843 kHz, 884 mV, 699 mW, 482 Cx
1900 kHz, 884 mV, 719 mW, 480 Cx
1996 kHz, 916 mV, 814 mW, 484 Cx
2112 kHz, 916 mV, 861 mW, 483 Cx
2208 kHz, 916 mV, 963 mW, 522 Cx
2323 kHz, 940 mV, 1063 mW, 520 Cx
2400 kHz, 956 mV, 1135 mW, 519 Cx
Your dynamic-power-coefficient for cpu 6: 489
As you can see, the calculations aren't perfectly consistent but
roughly you could say about 480 for big and 137 for little.
The ratio between these numbers isn't quite the same as the ratio
between the two numbers that Qualcomm used. Perhaps this is because
Qualcomm measured something slightly different than the 64-bit version
of dhrystone 2.2 or perhaps it's because they fudged these numbers a
bit (and fudged the capacity-dmips-mhz). As per discussion [2], let's
use the numbers I came up with and also un-fudge
capacity-dmips-mhz. While unfudging capacity-dmips-mhz, let's scale it
so that bigs are 1024 which seems to be the common practice.
In general these numbers don't need to be perfectly exact. In fact,
they can't be since the CPU power depends a lot on what's being run on
the CPU and the big/little CPUs are each more or less efficient in
different operations. Historically running the 32-bit vs. 64-bit
versions of dhrystone produced notably different numbers, though I
didn't test this time.
We also need to scale all of the sustainable-power numbers by the same
amount. I scale ones related to the big CPUs by the adjustment I made
to the big dynamic-power-coefficient and the ones related to the
little CPUs by the adjustment I made to the little
dynamic-power-coefficient.
[2] https://lore.kernel.org/r/[email protected]/
Fixes: 71f873169a ("arm64: dts: qcom: sc7180: Add dynamic CPU power coefficients")
Signed-off-by: Douglas Anderson <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20210902145127.v2.1.I049b30065f3c715234b6303f55d72c059c8625eb@changeid
There is some debate about whether it's deemed acceptable to call
dev_err_probe() if you know that the error code can never be
-EPROBE_DEFER. Clarify in the function comments that this is
OK. Specifically this makes us able to transform code like this:
ret = do_something_that_cant_defer();
if (ret < 0) {
dev_err(dev, "The foo failed to bar (%pe)\n", ERR_PTR(ret));
return ret;
}
to code like this:
ret = do_something_that_cant_defer();
if (ret < 0)
return dev_err_probe(dev, ret, "The foo failed to bar\n");
It is also possible that in the future folks might want a CONFIG
option to strip out all probe error strings to save space (keeping
non-probe errors) with the argument that probe errors rarely happen
after bringup. Having probe errors reported with a consistent function
would allow that.
Cc: Stephen Boyd <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20210916161931.1.I32bea713bd6c6fb419a24da73686145742b6c117@changeid
Signed-off-by: Greg Kroah-Hartman <[email protected]>
As discussed in the patch ("dt-bindings: drm/panel-simple: Introduce
generic eDP panels") we can actually support probing eDP panels at
runtime instead of hardcoding what panel is connected. Add support to
the panel-edp driver for this.
We'll implement a solution like this:
* We'll read in two delays from the device tree that are used for
powering up the panel the initial time (to read the EDID).
* In the EDID we can find a 32-bit ID that identifies what panel we've
found. From this ID we can look up the full set of delays.
After this change we'll still need to add per-panel delays into the
panel-simple driver but we will no longer need to specify exactly
which panel is connected to which board in the device tree. Nicely,
any panels that are only supported this way also don't need to
hardcode mode data since it's guaranteed that we can get that through
the EDID.
This patch will seed the ID-to-delay table with a few panels that I
have access to, many of which are on sc7180-trogdor devices.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.15.Id9c96cba4eba3e5ee519bfb09cd64b39f2490293@changeid
While cleaning up the descriptions of the delay for eDP panels I
realized that we'd have a bug if any panels need the
"prepare_to_enable" but HPD handling isn't happening in the panel
driver. Let's put in a stopgap to at least make us not violate
timings. This is not perfectly optimal but trying to do better is
hard. At the moment only 2 panels specify this delay and only 30 ms is
at stake. These panels are also currently hooked up with "hpd-gpios"
so effectively this "fix" is just a theoretical fix and won't actually
do anything for any devices currently supported in mainline.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.13.Ia8288d36df4b12770af59ae3ff73ef7e08fb4e2e@changeid
Now that the delays are named / described with eDP-centric names, it
becomes clear that we should really specify the "hpd_reliable" and
"hpd_absent" separately without taking the other into account. Let's
fix it.
This should be a no-op change and just adjust how we specify
things. The actual delays should be the same before and after for the
one panel that currently species both "hpd_reliable" and "hpd_absent".
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.12.I2522235fca3aa6790ede0bf22a93d79a1f694e6b@changeid
Now that the eDP panel driver only handles eDP panels we can make
better sense of the delays here. Let's describe them in terms of the
standard eDP timing diagram from the eDP spec.
As part of this, it becomes pretty clear that some eDP panels have too
long of a "hpd_reliable_delay". This used to be the "prepare"
delay. It's the fixed delay that we do in the panel driver after
powering on our panel before we look at the HPD signal. To understand
this better, first realize that there could be 3 paths we follow
depending on how HPD is hooked up. Let's walk through them:
1. HPD is handled by the eDP controller driver. Until "recently"
(commit 48834e6084 ("drm/panel-simple: Support hpd-gpios for
delaying prepare()") in May 2020) this was the only supported
way. This is supposed to be when the controller driver gets HPD
straight to a dedicated pin. In this case the controller driver
should be waiting for HPD in its pre_enable() routine which should
be called right after the panel's prepare() function is
called. That means that the old "prepare" delay was only needed as
a delay after powering the panel but before looking at HPD.
2. HPD is handled via hpd-gpios in the panel. This is much like #1 but
much easier to follow since all the handling is in the panel
driver.
3. The no-hpd case. This is also easy to follow.
In any case, even though it seems like some old panel data was using
this incorrectly, let's not touch the old data structures but we'll
add a note indicating that something seems off.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.11.I2d798dd015332661c5895ef744bc8ec5cd2e06ca@changeid
Not all panels in panel-simple were marked what type of panel they
were. I searched through ARM/ARM64 Chromebooks or Chromebook-related
reference boards that I was aware of and found some panels that needed
to be moved. I also skimmed for panels that had no mode and were "big"
since it's quite rare to see a small eDP panel. Here's what I found:
* auo,b101ean01 - rk3288-veyron-minnie
* auo,b133htn01 - exynos5800-peach-pi
* auo,b133xtn01 - tegra124-nyan-big
* boe,nv101wxmn51 - rk3399-gru-bob
* innolux,p120zdg-bf1 - sdm845-cheza
* lg,lp079qx1-sp0v - rk3399-evb and similar
* lg,lp097qx1-spa1 - According to commit 0355dde26e ("drm/panel:
simple: Add support for LG LP097QX1-SPA1 panel") this is an eDP
panel.
* lg,lp129qe - tegra124-venice2
* samsung,lsn122dl01-c01 - According to commit 0330eaf390
("drm/panel: simple: Add support for Samsung LSN122DL01-C01 panel")
this is an eDP panel.
* samsung,ltn140at29-301 - tegra124-nyan-blaze
* sharp,ld-d5116z01b - According to commit cd5e1cbe1f ("drm/panel:
simple: Add support for Sharp LD-D5116Z01B panel") this is an eDP
panel.
* sharp,lq123p1jx31 - rk3399-gru-kevin
* starry,kr122ea0sra - rk3399-gru-gru (reference board, not upstream)
I won't promise that I didn't miss a single panel, but that's fairly
complete I think.
I'm not sure the full impact of the fact that they didn't have the
connector type specified, but at least as of commit 9f069c6fbc
("drm/panel: panel-simple: add default connector_type") we may have
been accidentally thinking of them as DPI panels. We also would
certainly have had a warning. In any case since we don't want to
support anything eDP in the old simple-panel driver, we should move
these.
Cc: Yakir Yang <[email protected]>
Cc: Jeffrey Hugo <[email protected]>
Cc: Thierry Reding <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.8.I84e36f9f86d5d693fce0641a55ddb264a518a947@changeid
The panel-simple driver handles way too much. Let's start trying to
get a handle on it by splitting out the eDP panels. This patch does
this:
1. Start by copying simple-panel verbatim over to a new driver,
simple-panel-edp.
2. Rename "panel_simple" to "panel_edp" in the new driver.
3. Keep only panels marked with `DRM_MODE_CONNECTOR_eDP` in the new
driver. Remove those panels from the old driver.
4. Remove all recent "DP AUX bus" stuff from the old driver. The DP
AUX bus is only possible on DP panels.
5. Remove all DSI / MIPI related functions from the new driver.
6. Remove bus_format / bus_flags from eDP driver. These things don't
seem to make any sense for eDP panels so let's stop filling in made
up stuff.
In the end we end up with a bunch of duplicated code for now. Future
patches will try to address _some_ of this duplicated code though some
of it will be unavoidable.
NOTE: This may not actually move all eDP panels over to the new driver
since not all panels were properly marked with
`DRM_MODE_CONNECTOR_eDP`. A future patch will attempt to move wayward
panels I could identify but even so there may be some missed.
Suggested-by: Sam Ravnborg <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.7.I0a2f75bb822d17ce06f5b147734764eeb0c3e3df@changeid
In the patch ("drm/edid: Allow the querying/working with the panel ID
from the EDID") we introduced a different way of working with the
panel ID stored in the EDID. Let's use this new way for the quirks
code.
Advantages of the new style:
* Smaller data structure size. Saves 4 bytes per panel.
* Iterate through quirks structure with just "==" instead of strncmp()
* In-kernel storage is more similar to what's stored in the EDID
itself making it easier to grok that they are referring to the same
value.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Jani Nikula <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.4.I6103ce2b16e5e5a842b14c7022a034712b434609@changeid
EDIDs have 32-bits worth of data which is intended to be used to
uniquely identify the make/model of a panel. This has historically
been used only internally in the EDID processing code to identify
quirks with panels.
We'd like to use this panel ID in panel drivers to identify which
panel is hooked up and from that information figure out power sequence
timings. Let's expose this information from the EDID code and also
allow it to be accessed early, before a connector has been created.
To make matching in the panel drivers code easier, we'll return the
panel ID as a 32-bit value. We'll provide some functions for
converting this value back and forth to something more human readable.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Reviewed-by: Jani Nikula <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.3.I4a672175ba1894294d91d3dbd51da11a8239cf4a@changeid
eDP panels generally contain almost everything needed to control them
in their EDID. This comes from their DP heritage were a computer needs
to be able to properly control pretty much any DP display that's
plugged into it.
The one big issue with eDP panels and the reason that we need a panel
driver for them is that the power sequencing can be different per
panel.
While it is true that eDP panel sequencing can be arbitrarily complex,
in practice it turns out that many eDP panels are compatible with just
some slightly different delays. See the contents of the bindings file
introduced in this patch for some details.
The fact that eDP panels are 99% probable and that the power
sequencing (especially power up) can be compatible between many panels
means that there's a constant desire to plug multiple different panels
into the same board. This could be for second sourcing purposes or to
support multiple SKUs (maybe a 11" and a 13", for instance).
As discussed [1], it should be OK to support this by adding two
properties to the device tree to specify the delays needed for
powering up the panel the first time. We'll create a new "edp-panel"
bindings file and define the two delays that might need to be
specified. NOTE: in the vast majority of the cases (HPD is hooked up
and isn't glitchy or is debounced) even these delays aren't needed.
[1] https://lore.kernel.org/r/CAD=FV=VZYOMPwQZzWdhJGh5cjJWw_EcM-wQVEivZ-bdGXjPrEQ@mail.gmail.com
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.1.I1116e79d34035338a45c1fc7cdd14a097909c8e0@changeid
When I added nvmem_cell_read_variable_le_u32() and
nvmem_cell_read_variable_le_u64() I forgot to add the "static inline"
stub functions for when CONFIG_NVMEM wasn't defined. Add them
now. This was causing problems with randconfig builds that compiled
`drivers/soc/qcom/cpr.c`.
Fixes: 6feba6a62c ("PM: AVS: qcom-cpr: Use nvmem_cell_read_variable_le_u32()")
Fixes: a28e824fb8 ("nvmem: core: Add functions to make number reading easy")
Reported-by: kernel test robot <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Signed-off-by: Srinivas Kandagatla <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
When I booted up on a board that had a slightly different codec
stuffed on it, I got this message at bootup:
rt5682 9-001a: Device with ID register 6749 is not rt5682
That's normal/expected, but what wasn't normal was the splat that I
got after:
WARNING: CPU: 7 PID: 176 at drivers/regulator/core.c:2151 _regulator_put+0x150/0x158
pc : _regulator_put+0x150/0x158
...
Call trace:
_regulator_put+0x150/0x158
regulator_bulk_free+0x48/0x70
devm_regulator_bulk_release+0x20/0x2c
release_nodes+0x1cc/0x244
devres_release_all+0x44/0x60
really_probe+0x17c/0x378
...
This is because the error paths don't turn off the regulator. Let's
fix that.
Fixes: 0ddce71c21 ("ASoC: rt5682: add rt5682 codec driver")
Fixes: 87b42abae9 ("ASoC: rt5682: Implement remove callback")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/20210811081751.v2.1.I4a1d9aa5d99e05aeee15c2768db600158d76cab8@changeid
Signed-off-by: Mark Brown <[email protected]>
Putting the panel under the bridge chip (under the aux-bus node)
allows the panel driver to get access to the DP AUX bus, enabling all
sorts of fabulous new features.
While we're at this, get rid of a level of hierarchy for the panel
node. It doesn't need "ports / port" and can just have a "port" child.
For Linux, this patch has a hard requirement on the patches adding DP
AUX bus support to the ti-sn65dsi86 bridge chip driver. See the patch
("drm/bridge: ti-sn65dsi86: Add support for the DP AUX bus").
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Acked-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/20210611101711.v10.11.Ibdb7735fb1844561b902252215a69526a14f9abd@changeid
Signed-off-by: Bjorn Andersson <[email protected]>
Let's delete the private function cpr_read_efuse() since it does the
basically the same thing as the new API call
nvmem_cell_read_variable_le_u32().
Differences between the new API call and the old private function:
* less error printing (I assume this is OK).
* will give an error if the value doesn't fit in 32-bits (the old code
would have truncated silently).
Reviewed-by: Bjorn Andersson <[email protected]>
Acked-by: Niklas Cassel <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/20210521134437.v2.1.Id1c70158722750aec0673d60c12e46a9c66bbfed@changeid
Signed-off-by: Bjorn Andersson <[email protected]>
The Samsung ATNA33XC20 panel is an AMOLED eDP panel that has backlight
control over the DP AUX channel.
This panel is _almost_ able to be controlled in a "simple" way (and it
originally was implemented in panel-simple.c), but it's really
impossible to get the backlight semantics right there without adding
wacky special-case code to panel-simple. Let's give up and clone the
parts of panel-simple that we need and implement the power sequence
that this panel needs.
NOTE: we'll still leave the devicetree bindings alone. Even though the
power-sequencing is non-standard the bindings are still "simple".
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730084534.v2.6.I3a2900080f8749d2bb4baf49ca902db4b0e1df7d@changeid
This reverts commit 18a1488bf1.
Those delays were added to support the Samsung ATNA33XC20
panel. However, we've moving that to its own panel driver and out of
panel-simple. That means we don't need the ability to specify this
delay.
NOTE: it's unlikely we want to keep this delay "just in case" some
other panel needs it. The enable-gpio and the power supply are really
supposed to be different ways to specify the same thing: the main
enable of the panel. Supporting a delay between them doesn't really
make sense.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730084534.v2.5.Ie44e3e5b7a926392541d575ca84c56931596513f@changeid
When testing with a panel that's apparently a little more persnickety
about the correct power sequence (specifically Samsung ATNA33XC20), we
found that the ti-sn65dsi86 was doing things just slightly wrong.
Looking closely at the ti-sn65dsi86's datasheet, the power off
sequence is supposed to be:
1. Clear VSTREAM_ENABLE bit
2. Stop DSI stream from GPU. DSI lanes must be placed in LP11 state.
3. Program the ML_TX_MODE to 0x0 (OFF)
4. Program the DP_NUM_LANES register to 0x0
5. Clear the DP_PLL_EN bit.
6. Deassert the EN pin.
7. Remove power from supply pins
Since we were doing the whole sequence in the "disable", I believe
that step #2 (stopping the DSI stream from the GPU) wasn't
happening. We also weren't setting DP_NUM_LANES to 0.
Let's fix this.
NOTE: things are a little asymmetric now. For instance, we turn the
PLL on in "enable" but now we're not turning it off until
"post_disable". It would seem to make sense to move the PLL turning on
to "pre_enable" to match. Unfortunately, I don't believe that's
allowed. It looks as if (in the non-refclk mode which probably nobody
is using) we have to wait until the MIPI clock is there before we can
enable the PLL. In any case, the way it is here won't really
hurt--it'll just leave the PLL on a little longer.
Fixes: a095f15c00 ("drm/bridge: add support for sn65dsi86 bridge driver")
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Robert Foss <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730084534.v2.2.If8a8ec3bf1855cf0dbb62c005a71d6698c99c125@changeid
The function drm_edp_backlight_init() is defined such that the
"driver_pwm_freq_hz" parameter is optional--it's 0 if you don't want
to futz with it. If you follow this variable through, you'll find out
that if it's 0 we won't ever set the "bl->pwmgen_bit_count", leaving
it as 0.
That means that before using it in drm_edp_backlight_enable() we need
to check to see if it's non-zero.
Programming this field to zero was confusing the panel I tested with
(Samsung ATNA33XC20). The backlight still worked somewhat but the
brightness values didn't correspond to what they should have been.
Fixes: 867cf9cd73 ("drm/dp: Extract i915's eDP backlight code into DRM helpers")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730084534.v2.1.If017efce7116ae8ba015ed7def840c390a0e0c77@changeid
In commit 18eeef46d3 ("HID: i2c-hid: goodix: Tie the reset line to
true state of the regulator") I added a call to
regulator_register_notifier() but no call to unregister. That's a
bug. Let's use the devm variant to handle the unregistering.
Fixes: 18eeef46d3 ("HID: i2c-hid: goodix: Tie the reset line to true state of the regulator")
Signed-off-by: Douglas Anderson <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
The regulator for the touchscreen could be:
* A dedicated regulator just for the touchscreen.
* A regulator shared with something else in the system.
* An always-on regulator.
How we want the "reset" line to behave depends a bit on which of those
three cases we're in. Currently the code is written with the
assumption that it has a dedicated regulator, but that's not really
guaranteed to be the case.
The problem we run into is that if we leave the touchscreen powered on
(because someone else is requesting the regulator or it's an always-on
regulator) and we assert reset then we apparently burn an extra 67 mW
of power. That's not great.
Let's instead tie the control of the reset line to the true state of
the regulator as reported by regulator notifiers. If we have an
always-on regulator our notifier will never be called. If we have a
shared regulator then our notifier will be called when the touchscreen
is truly turned on or truly turned off.
Using notifiers like this nicely handles all the cases without
resorting to hacks like pretending that there is no "reset" GPIO if we
have an always-on regulator.
NOTE: if the regulator is on a shared line it's still possible that
things could be a little off. Specifically, this case is not handled
even after this patch:
1. Suspend goodix (send "sleep", goodix stops requesting regulator on)
2. Other regulator user turns off (regulator fully turns off).
3. Goodix driver gets notified and asserts reset.
4. Other regulator user turns on.
5. Goodix driver gets notified and deasserts reset.
6. Nobody resumes goodix.
With that set of steps we'll have reset deasserted but we will have
lost the results of the I2C_HID_PWR_SLEEP from the suspend path. That
means we might be in higher power than we could be even if the goodix
driver thinks things are suspended. Presumably, however, we're still
in better shape than if we were asserting "reset" the whole time. If
somehow the above situation is actually affecting someone and we want
to do better we can deal with it when we have a real use case.
Signed-off-by: Douglas Anderson <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Even after the DP AUX backlight on my board worked OK after applying
the patch ("drm/panel-simple: Power the panel when probing DP AUX
backlight") [1], I still noticed some strange timeouts being reported
by ti_sn_aux_transfer(). Digging, I realized the problem was this:
* Even though `enabled` in `struct dp_aux_backlight` was false, the
base backlight structure (`base` in that structure) thought that the
backlight was powered on.
* If userspace wrote to sysfs in this state then we'd try to enable
the backlight.
* Unfortunatley, enabling the backlight didn't work because the panel
itself wasn't powered.
We can only use the backlight if the panel is on and the panel is not
officially on when we probe (it's temporarily just on enough for us to
talk to it).
The important thing we want here is to get `BL_CORE_FBBLANK` set since
userspace can't mess with that. This will keep us disabled until
drm_panel enables us, which means that the panel is enabled
first. Ideally we'd just set this in our `props` before calling
devm_backlight_device_register() but the comments in the header file
are pretty explicit that we're not supposed to much with the `state`
ourselves. Because of this, there may be a small window where the
backlight device is registered and someone could try to tweak with the
backlight. This isn't likely to happen and even if it did, I don't
believe this causes any huge problem.
[1] https://lore.kernel.org/lkml/20210714093334.1.Idb41f87e5abae4aee0705db7458b0097fc50e7ab@changeid/
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714101744.1.Ifc22696b27930749915e383f0108b7bcdc015a6e@changeid
When I tried booting up a device that needed the DP AUX backlight, I
found an error in the logs:
panel-simple-dp-aux: probe of aux-ti_sn65dsi86.aux.0 failed with error -110
The aux transfers were failing because the panel wasn't powered. Just
like when reading the EDID we need to power the panel when trying to
talk to it. Add the needed pm_runtime calls.
After I do this I can successfully probe the panel and adjust the
backlight on my board.
Fixes: bfd451403d ("drm/panel-simple: Support DP AUX backlight")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714093334.1.Idb41f87e5abae4aee0705db7458b0097fc50e7ab@changeid
The comment in setup_fifo_xfer() about setting the watermark wasn't
quite proper grammar and also stopped making sense around commit
6d66507d9b ("spi: spi-geni-qcom: Don't wait to start 1st transfer if
transmitting"). After that commit we actually start the transfer
_before_ the watermark interrupt comes.
I don't think the comment really has any value anymore. We've already
got a comment when we grab the spinlock saying that our interrupt can
come any time as a result of the things in the locked section. Let's
just remove it.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Vinod Koul <[email protected]>
Link: https://lore.kernel.org/r/20210712085010.1.Ie3bb9f9d30d6475bb75251d32635194c1c72b9ee@changeid
Signed-off-by: Mark Brown <[email protected]>
We were getting a depmod error:
depmod: ERROR: Cycle detected: drm_kms_helper -> drm -> drm_kms_helper
It looks like the rule is that drm_kms_helper can call into drm, but
drm can't call into drm_kms_helper. That means we've got to move the
DP AUX backlight support into drm_dp_helper.
NOTE: as part of this, I didn't try to do any renames of the main
registration function. Even though it's in the drm_dp_helper, it still
feels very parallel to drm_panel_of_backlight().
Fixes: 10f7b40e4f ("drm/panel: add basic DP AUX backlight support")
Reported-by: Ville Syrjälä <[email protected]>
Reported-by: Thomas Zimmermann <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Rajeev Nandan <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712075933.v2.1.I23eb4cc5a680341e7b3e791632a635566fa5806a@changeid
Putting the panel under the bridge chip (under the aux-bus node)
allows the panel driver to get access to the DP AUX bus, enabling all
sorts of fabulous new features.
While we're at this, get rid of a level of hierarchy for the panel
node. It doesn't need "ports / port" and can just have a "port" child.
For Linux, this patch has a hard requirement on the patches adding DP
AUX bus support to the ti-sn65dsi86 bridge chip driver. See the patch
("drm/bridge: ti-sn65dsi86: Add support for the DP AUX bus").
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Acked-by: Bjorn Andersson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.11.Ibdb7735fb1844561b902252215a69526a14f9abd@changeid
As I was testing to make sure that the DEFER path worked well with my
patch series, I got tired of seeing this scary message in my logs just
because the panel needed to defer:
[drm:ti_sn_bridge_probe] *ERROR* could not find any panel node
Let's use dev_err_probe() which nicely quiets this error and also
simplifies the code a tiny bit. We'll also update other places in the
file which can use dev_err_probe().
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.10.I24bba069e63b1eea84443eef0c8535fd032a6311@changeid
This is really just a revert of commit 58074b08c0 ("drm/bridge:
ti-sn65dsi86: Read EDID blob over DDC"), resolving conflicts.
The old code failed to read the EDID properly in a very important
case: before the bridge's pre_enable() was called. The way things need
to work:
1. Read the EDID.
2. Based on the EDID, decide on video settings and pixel clock.
3. Enable the bridge w/ the desired settings.
The way things were working:
1. Try to read the EDID but fail; fall back to hardcoded values.
2. Based on hardcoded values, decide on video settings and pixel clock.
3. Enable the bridge w/ the desired settings.
4. Try again to read the EDID, it works now!
5. Realize that the hardcoded settings weren't quite right.
6. Disable / reenable the bridge w/ the right settings.
The reasons for the failures were twofold:
a) Since we never ran the bridge chip's pre-enable then we never set
the bit to ignore HPD. This meant the bridge chip didn't even _try_
to go out on the bus and communicate with the panel.
b) Even if we fixed things to ignore HPD, the EDID still wouldn't read
if the panel wasn't on.
Instead of reverting the code, we could fix it to set the HPD bit and
also power on the panel. However, it also works nicely to just let the
panel code read the EDID. Now that we've split the driver up we can
expose the DDC AUX channel bus to the panel node. The panel can take
charge of reading the EDID.
NOTE: in order for things to work, anyone that needs to read the EDID
will need to instantiate their panel using the new DP AUX bus (AKA by
listing their panel under the "aux-bus" node of the bridge chip in the
device tree).
In the future if we want to use the bridge chip to provide a full
external DP port (which won't have a panel) then we will have to
conditinally add EDID reading back in.
Suggested-by: Andrzej Hajda <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.9.I9330684c25f65bb318eff57f0616500f83eac3cc@changeid
On its own, this change looks a little strange and doesn't do too much
useful. To understand why we're doing this we need to look forward to
future patches where we're going to probe our panel using the new DP
AUX bus. See the patch ("drm/bridge: ti-sn65dsi86: Add support for the
DP AUX bus").
Let's think about the set of steps we'll want to happen when we have
the DP AUX bus:
1. We'll create the DP AUX bus.
2. We'll populate the devices on the DP AUX bus (AKA our panel).
3. For setting up the bridge-related functions of ti-sn65dsi86 we'll
need to get a reference to the panel.
If we do #1 - #3 in a single probe call things _mostly_ will work, but
it won't be massively robust. Let's explore.
First let's think of the easy case of no -EPROBE_DEFER. In that case
in step #2 when we populate the devices on the DP AUX bus it will
actually try probing the panel right away. Since the panel probe
doesn't defer then in step #3 we'll get a reference to the panel and
we're golden.
Second, let's think of the case when the panel returns
-EPROBE_DEFER. In that case step #2 won't synchronously create the
panel (it'll just add the device to the defer list to do it
later). Step #3 will fail to get the panel and the bridge sub-device
will return -EPROBE_DEFER. We'll depopulate the DP AUX bus. Later
we'll try the whole sequence again. Presumably the panel will
eventually stop returning -EPROBE_DEFER and we'll go back to the first
case where things were golden. So this case is OK too even if it's a
bit ugly that we have to keep creating / deleting the AUX bus over and
over.
So where is the problem? As I said, it's mostly about robustness. I
don't believe that step #2 (creating the sub-devices) is really
guaranteed to be synchronous. This is evidenced by the fact that it's
allowed to "succeed" by just sticking the device on the deferred
list. If anything about the process changes in Linux as a whole and
step #2 just kicks off the probe of the DP AUX endpoints (our panel)
in the background then we'd be in trouble because we might never get
the panel in step #3.
Adding an extra sub-device means we just don't need to worry about
it. We'll create the sub-device for the DP AUX bus and it won't go
away until the whole ti-sn65dsi86 driver goes away. If the bridge
sub-device defers (maybe because it can't find the panel) that won't
depopulate the DP AUX bus and so we don't need to worry about it.
NOTE: there's a little bit of a trick here. Though the AUX channel can
run without the MIPI-to-eDP bits of the code, the MIPI-to-eDP bits
can't run without the AUX channel. We could come up a complicated
signaling scheme (have the MIPI-to-eDP bits return EPROBE_DEFER for a
while or wait on some sort of completion), but it seems simple enough
to just not even bother creating the bridge device until the AUX
channel probes. That's what we'll do.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.7.If89144992cb9d900f8c91a8d1817dbe00f543720@changeid
The panel-simple driver can already have devices instantiated as
platform devices or MIPI DSI devices. Let's add a 3rd way to
instantiate it: as DP AUX endpoint devices.
At the moment there is no benefit to instantiating it in this way,
but:
- In the next patch we'll give it access to the DDC channel via the DP
AUX bus.
- Possibly in the future we may use this channel to configure the
backlight.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.5.Iada41f76a7342354bae929d0bb3ceba40f27f0ea@changeid
Historically "simple" eDP panels have been handled by panel-simple
which is a basic platform_device. In the device tree, the panel node
was at the top level and not connected to anything else.
Let's change it so that, instead, panels can be represented as being
children of the "DP AUX bus". Essentially we're saying that the
hierarchy that we're going to represent is the "control" connections
between devices. The DP AUX bus is a control bus provided by an eDP
controller (the parent) and consumed by a device like a panel (the
child).
The primary incentive here is to cleanly provide the panel driver the
ability to communicate over the AUX bus while handling lifetime issues
properly. The panel driver may want the AUX bus for controlling the
backlight or querying the panel's EDID.
The idea for this bus's design was hashed out over IRC [1].
[1] https://people.freedesktop.org/~cbrill/dri-log/?channel=dri-devel&date=2021-05-11
Cc: Laurent Pinchart <[email protected]>
Cc: Lyude Paul <[email protected]>
Cc: Rajeev Nandan <[email protected]>
Suggested-by: Laurent Pinchart <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.4.I787c9ba09ed5ce12500326ded73a4f7c9265b1b3@changeid
We want to be able to list an eDP panel as a child of an eDP
controller node to represent the fact that the panel is connected to
the controller's DP AUX bus. Though the panel and the controller are
connected in several ways, the DP AUX bus is the primary control
interface between the two and thus makes the most sense to model in
device tree hierarchy.
Listing a panel in this way makes it possible for the panel driver to
easily get access to the DP AUX bus that it resides on, which can be
useful to help in auto-detecting the panel and for turning on various
bits.
NOTE: historically eDP panels were _not_ listed under their controller
but were listed at the top level of the device tree. This will still
be supported for backward compatibility (and while DP controller
drivers are adapted to support the new DT syntax) but should be
considered deprecated since there is no downside to listing the panel
under the controller.
For now, the DP AUX bus bindings will only support an eDP panel
underneath. It's possible it could be extended to allow having a DP
connector under it in the future.
NOTE: there is no "Example" in this bindings file. Yikes! This avoids
duplicating the same example lots of places. See users of the aux bus
(like ti-sn65dsi86) for examples.
The idea for this bus's design was hashed out over IRC [1].
[1] https://people.freedesktop.org/~cbrill/dri-log/?channel=dri-devel&date=2021-05-11
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.2.Id3c048d22e72a9f90084a543b5b4e3f43bc9ab62@changeid
The HPD (Hot Plug Detect) signal is present in many (probably even
"most") eDP panels. For eDP, this signal isn't actually used for
detecting hot-plugs of the panel but is more akin to a "panel ready"
signal. After you provide power to the panel, panel timing diagrams
typically say that you should wait for HPD to be asserted (or wait a
fixed amount of time) before talking to the panel.
The panel-simple bindings describes many eDP panels and many of these
panels provide the HPD signal. We should add the HPD-related
properties to the panel-simple bindings. The HPD properties are
actually defined in panel-common.yaml, so adding them here just
documents that they are OK for panels handled by the panel-simple
bindings.
NOTE: whether or not we'd include HPD properties in the panel node is
more a property of the board design than the panel itself. For most
boards using these eDP panels everything "magically" works without
specifying any HPD properties and that's been why we haven't needed to
allow the HPD properties earlier. On these boards the HPD signal goes
directly to a dedicated "HPD" input to the eDP controller and this
connection doesn't need to be described in the device tree. The only
time the HPD properties are needed in the device tree are if HPD is
hooked up to a GPIO or if HPD is normally on the panel but isn't used
on a given board. That means that if we don't allow the HPD properties
in panel-simple then one could argue that we've got to boot all eDP
panels (or at least all those that someone could conceivably put on a
system where HPD goes to a GPIO or isn't hooked up) from panel-simple.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210611101711.v10.1.Ieb731d23680db4700cc41fe51ccc73ba0b785fb7@changeid
The PM Runtime docs specifically call out the need to call
pm_runtime_dont_use_autosuspend() in the remove() callback if
pm_runtime_use_autosuspend() was called in probe():
> Drivers in ->remove() callback should undo the runtime PM changes done
> in ->probe(). Usually this means calling pm_runtime_disable(),
> pm_runtime_dont_use_autosuspend() etc.
We should do this. This fixes a warning splat that I saw when I was
testing out the panel-simple's remove().
Fixes: 3235b0f20a ("drm/panel: panel-simple: Use runtime pm to avoid excessive unprepare / prepare")
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210517130450.v7.1.I9e947183e95c9bd067c9c1d51208ac6a96385139@changeid
I don't believe that it ever makes sense to read the EDID when a panel
is not powered and the powering on of the panel is the job of
prepare(). Let's make sure that this happens before we try to read the
EDID. We use the pm_runtime functions directly rather than directly
calling the normal prepare() function because the pm_runtime functions
are definitely refcounted whereas it's less clear if the prepare() one
is.
NOTE: I'm not 100% sure how EDID reading was working for folks in the
past, but I can only assume that it was failing on the initial attempt
and then working only later. This patch, presumably, will fix that. If
some panel out there really can read the EDID without powering up and
it's a big advantage to preserve the old behavior we can add a
per-panel flag. It appears that providing the DDC bus to the panel in
the past was somewhat uncommon in any case.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.17.Ibd31b8f7c73255d68c5c9f5b611b4bfaa036f727@changeid
Let's reorganize how we init and turn on the reference clock in the
code to allow us to turn it on early (even before pre_enable()) so
that we can read the EDID early. This is handy for eDP because:
- We always assume that a panel is there.
- Once we report that a panel is there we get asked to read the EDID.
- Pre-enable isn't called until we know what pixel clock we want to
use and we're ready to turn everything on. That's _after_ we get
asked to read the EDID.
NOTE: the above only works out OK if we "refclk" is provided. Though I
don't have access to any hardware that uses ti-sn65dsi86 and _doesn't_
provide a "refclk", I believe that we'll have trouble reading the EDID
at bootup in that case. Specifically I believe that if there's no
"refclk" we need the MIPI source clock to be active before we can
successfully read the EDID. My evidence here is that, in testing, I
couldn't read the EDID until I turned on the DPPLL in the bridge chip
and that the DPPLL needs the input clock to be active.
Since this is hard to support, let's punt trying to handle this case
if there's no "refclk". In that case we'll enable comms in
pre_enable() like we always did.
I don't believe there are any users of the ti-sn65dsi86 bridge chip
that _don't_ use "refclk". The bridge chip is _very_ inflexible in
that mode. The only time I've seen that mode used was for some really
early prototype hardware that was thrown in the e-waste bin years ago
when we realized how inflexible it was.
Even if someone is using the bridge chip without the "refclk" they're
in no worse shape than they were before the (fairly recent) commit
58074b08c0 ("drm/bridge: ti-sn65dsi86: Read EDID blob over DDC").
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.13.Ie8cf556114953c6e7634564cc0d3ddbd103cb96c@changeid
When I added support for the hpd-gpio to simple-panel in commit
48834e6084 ("drm/panel-simple: Support hpd-gpios for delaying
prepare()"), I added a special case to handle a circular dependency I
was running into on the ti-sn65dsi86 bridge chip. On my board the
hpd-gpio is actually provided by the bridge chip. That was causing
some circular dependency problems that I had to work around by getting
the hpd-gpio late.
I've now reorganized the ti-sn65dsi86 bridge chip driver to be a
collection of sub-drivers. Now the GPIO part can probe separately and
that breaks the chain. Let's get rid of the old code to clean things
up.
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.10.I40eeedc23459d1e3fc96fa6cdad775d88c6e706c@changeid
Let's use the newly minted aux bus to break up the driver into sub
drivers. We're not doing a full breakup here: all the code is still in
the same file and remains largely untouched. The big goal here of
using sub-drivers is to allow part of our code to finish probing even
if some other code needs to defer. This can solve some chicken-and-egg
problems. Specifically:
- In commit 48834e6084 ("drm/panel-simple: Support hpd-gpios for
delaying prepare()") we had to add a bit of a hack to simpel-panel
to support HPD showing up late. We can get rid of that hack now
since the GPIO part of our driver can finish probing early.
- We have a desire to expose our DDC bus to simple-panel (and perhaps
to a backlight driver?). That will end up with the same
chicken-and-egg problem. A future patch to move this to a sub-driver
will fix it.
- If/when we support the PWM functionality present in the bridge chip
for a backlight we'll end up with another chicken-and-egg
problem. If we allow the PWM to be a sub-driver too then it solves
this problem.
Signed-off-by: Douglas Anderson <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423095743.v5.9.I3e68fa38c4ccbdbdf145cad2b01e83a1e5eac302@changeid
Douglas Anderson