On Mon, Apr 12, 2021 at 05:31:38PM +0800, dillon.minfei@xxxxxxxxx wrote: > 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. This doesn't make much sense as console_write can be called in any context. And where's the deadlock you claim to be fixing here? > 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) Johan
