BackPup/Linux
1
0 Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-10-07 05:31:08 -04:00
Code Issues Packages Projects Releases Wiki Activity

serial: sunplus: Use uart_prepare_sysrq_char().

Browse Source 
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.

Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.

Cc: Hammer Hsieh <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Sebastian Andrzej Siewior authored and Greg Kroah-Hartman committed 2024-03-02 22:06:21 +01:00
1 parent 51f7ed071c
commit e544127cc1
1 file changed
+6 -12
Download Patch File Download Diff File Expand all files Collapse all files
drivers/tty/serial/sunplus-uart.c
+6 -12
View File
@@ -260,7 +260,7 @@ static void receive_chars(struct uart_port *port)
if (port->ignore_status_mask & SUP_DUMMY_READ)
goto ignore_char;
if (uart_handle_sysrq_char(port, ch))
if (uart_prepare_sysrq_char(port, ch))
goto ignore_char;
uart_insert_char(port, lsr, SUP_UART_LSR_OE, ch, flag);
@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int irq, void *args)
if (isc & SUP_UART_ISC_TX)
transmit_chars(port);
uart_port_unlock(port);
uart_unlock_and_check_sysrq(port);
return IRQ_HANDLED;
}
@@ -512,22 +512,16 @@ static void sunplus_console_write(struct console *co,
unsigned long flags;
int locked = 1;
local_irq_save(flags);
if (sunplus_console_ports[co->index]->port.sysrq)
locked = 0;
else if (oops_in_progress)
locked = uart_port_trylock(&sunplus_console_ports[co->index]->port);
if (oops_in_progress)
locked = uart_port_trylock_irqsave(&sunplus_console_ports[co->index]->port, &flags);
else
uart_port_lock(&sunplus_console_ports[co->index]->port);
uart_port_lock_irqsave(&sunplus_console_ports[co->index]->port, &flags);
uart_console_write(&sunplus_console_ports[co->index]->port, s, count,
sunplus_uart_console_putchar);
if (locked)
uart_port_unlock(&sunplus_console_ports[co->index]->port);
local_irq_restore(flags);
uart_port_unlock_irqrestore(&sunplus_console_ports[co->index]->port, flags);
}
static int __init sunplus_console_setup(struct console *co, char *options)