[ALSA] Fix possible races in timer callbacks

Fix possible races in timer callbacks.

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

3 files changed, 11 insertions, 9 deletions

diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index a276f7c..1861175 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)
diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c
index ee67b52..8687ae3 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);
 }
diff --git a/sound/drivers/opl3/opl3_midi.c b/sound/drivers/opl3/opl3_midi.c
index 48c480e..1b6f227 100644
--- a/sound/drivers/opl3/opl3_midi.c
+++ b/sound/drivers/opl3/opl3_midi.c
@@ -238,10 +238,11 @@ void snd_opl3_timer_func(unsigned long data)
 {
 
 	struct snd_opl3 *opl3 = (struct snd_opl3 *)data;
+	unsigned long flags;
 	int again = 0;
 	int i;
 
-	spin_lock(&opl3->sys_timer_lock);
+	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
 	for (i = 0; i < opl3->max_voices; i++) {
 		struct snd_opl3_voice *vp = &opl3->voices[i];
 		if (vp->state > 0 && vp->note_off_check) {
@@ -257,7 +258,7 @@ void snd_opl3_timer_func(unsigned long data)
 	} else {
 		opl3->sys_timer_status = 0;
 	}
-	spin_unlock(&opl3->sys_timer_lock);
+	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
 }
 
 /*