From: dillon min <dillon.minfei@xxxxxxxxx> To avoid potential deadlock in spin_lock usage, use spin_lock_irqsave, spin_trylock_irqsave(), spin_unlock_irqrestore() in process context. remove unused local_irq_save/restore call. Cc: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx> Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> Cc: Gerald Baeza <gerald.baeza@xxxxxxxxxxx> Cc: Erwan Le Ray <erwan.leray@xxxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: dillon min <dillon.minfei@xxxxxxxxx> --- v2: remove unused code from stm32_usart_threaded_interrupt() according from Greg's review. drivers/tty/serial/stm32-usart.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index b3675cf25a69..b1ba5e36e36e 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -1354,13 +1354,12 @@ static void stm32_usart_console_write(struct console *co, const char *s, u32 old_cr1, new_cr1; int locked = 1; - local_irq_save(flags); if (port->sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock(&port->lock); + locked = spin_trylock_irqsave(&port->lock, flags); else - spin_lock(&port->lock); + spin_lock_irqsave(&port->lock, flags); /* Save and disable interrupts, enable the transmitter */ old_cr1 = readl_relaxed(port->membase + ofs->cr1); @@ -1374,8 +1373,7 @@ static void stm32_usart_console_write(struct console *co, const char *s, writel_relaxed(old_cr1, port->membase + ofs->cr1); if (locked) - spin_unlock(&port->lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&port->lock, flags); } static int stm32_usart_console_setup(struct console *co, char *options) -- 2.7.4