[ALSA] Fix possible races in timer callbacks

Fix possible races in timer callbacks.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 3 insertions, 2 deletions

diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c
index ee67b522d259..8687ae3c66b8 100644
--- a/sound/drivers/mpu401/mpu401_uart.c
+++ b/sound/drivers/mpu401/mpu401_uart.c
@@ -133,12 +133,13 @@ irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id, struct pt_regs *reg
 static void snd_mpu401_uart_timer(unsigned long data)
 {
         struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
+        unsigned long flags;
 
-        spin_lock(&mpu->timer_lock);
+        spin_lock_irqsave(&mpu->timer_lock, flags);
         /*mpu->mode |= MPU401_MODE_TIMER;*/
         mpu->timer.expires = 1 + jiffies;
         add_timer(&mpu->timer);
-        spin_unlock(&mpu->timer_lock);
+        spin_unlock_irqrestore(&mpu->timer_lock, flags);
         if (mpu->rmidi)
                 _snd_mpu401_uart_interrupt(mpu);
 }