7:31 p.m.
From: dillon min <dillon.minfei(a)gmail.com>
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(a)foss.st.com>
Cc: Maxime Coquelin <mcoquelin.stm32(a)gmail.com>
Cc: Gerald Baeza <gerald.baeza(a)foss.st.com>
Cc: Erwan Le Ray <erwan.leray(a)foss.st.com>
Reported-by: kernel test robot <lkp(a)intel.com>
Signed-off-by: dillon min <dillon.minfei(a)gmail.com>
---
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