GuillaumeHemmen/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2024-11-01 13:03:25 +01:00
Code Issues Projects Releases Packages Wiki Activity

serial: omap: 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.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-7-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sebastian Andrzej Siewior 2024-03-01 22:45:19 +01:00 committed by Greg Kroah-Hartman
parent 4e5788c099
commit 63bd93ac61
1 changed files with 6 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
drivers/tty/serial/omap-serial.c
View file

@ -508,7 +508,7 @@ static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
up->port.icount.rx++;
if (uart_handle_sysrq_char(&up->port, ch))
if (uart_prepare_sysrq_char(&up->port, ch))
return;
uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, TTY_NORMAL);
@ -563,7 +563,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
}
} while (max_count--);
uart_port_unlock(&up->port);
uart_unlock_and_check_sysrq(&up->port);
tty_flip_buffer_push(&up->port.state->port);
@ -1212,13 +1212,10 @@ serial_omap_console_write(struct console *co, const char *s,
unsigned int ier;
int locked = 1;
local_irq_save(flags);
if (up->port.sysrq)
locked = 0;
else if (oops_in_progress)
locked = uart_port_trylock(&up->port);
if (oops_in_progress)
locked = uart_port_trylock_irqsave(&up->port, &flags);
else
uart_port_lock(&up->port);
uart_port_lock_irqsave(&up->port, &flags);
/*
* First save the IER then disable the interrupts
@ -1245,8 +1242,7 @@ serial_omap_console_write(struct console *co, const char *s,
check_modem_status(up);
if (locked)
uart_port_unlock(&up->port);
local_irq_restore(flags);
uart_port_unlock_irqrestore(&up->port, flags);
}
static int __init