[ALSA] Fix possible races in timer callbacks

Fix possible races in timer callbacks.

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

1 files changed, 5 insertions, 5 deletions

diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index a276f7c8036..18611757174 100644
--- a/sound/drivers/dummy.c
+++ b/sound/drivers/dummy.c
@@ -231,8 +231,9 @@ static int snd_card_dummy_pcm_prepare(struct snd_pcm_substream *substream)
 static void snd_card_dummy_pcm_timer_function(unsigned long data)
 {
         struct snd_dummy_pcm *dpcm = (struct snd_dummy_pcm *)data;
+        unsigned long flags;
         
-        spin_lock(&dpcm->lock);
+        spin_lock_irqsave(&dpcm->lock, flags);
         dpcm->timer.expires = 1 + jiffies;
         add_timer(&dpcm->timer);
         dpcm->pcm_irq_pos += dpcm->pcm_jiffie;
@@ -240,11 +241,10 @@ static void snd_card_dummy_pcm_timer_function(unsigned long data)
         dpcm->pcm_buf_pos %= dpcm->pcm_size;
         if (dpcm->pcm_irq_pos >= dpcm->pcm_count) {
                 dpcm->pcm_irq_pos %= dpcm->pcm_count;
-                spin_unlock(&dpcm->lock);
+                spin_unlock_irqrestore(&dpcm->lock, flags);
                 snd_pcm_period_elapsed(dpcm->substream);
-                spin_lock(&dpcm->lock);
-        }
-        spin_unlock(&dpcm->lock);
+        } else
+                spin_unlock_irqrestore(&dpcm->lock, flags);
 }
 
 static snd_pcm_uframes_t snd_card_dummy_pcm_pointer(struct snd_pcm_substream *substream)