[ALSA] timers: add module refcounting for global timers

Modules: RTC timer driver,Timer Midlevel

Add a module pointer to the timer structure and use it for refcounting
instead of the card's module pointer to prevent the global timer
modules (rtctimer and hpetimer) from being removed while in use.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

3 files changed, 8 insertions, 4 deletions

diff --git a/include/sound/timer.h b/include/sound/timer.h
index 1898511a0f3..b55f38ae56e 100644
--- a/include/sound/timer.h
+++ b/include/sound/timer.h
@@ -88,6 +88,7 @@ struct _snd_timer_hardware {
 struct _snd_timer {
 	snd_timer_class_t tmr_class;
 	snd_card_t *card;
+	struct module *module;
 	int tmr_device;
 	int tmr_subdevice;
 	char id[64];
diff --git a/sound/core/rtctimer.c b/sound/core/rtctimer.c
index 8762ff8938c..c3c18568207 100644
--- a/sound/core/rtctimer.c
+++ b/sound/core/rtctimer.c
@@ -124,7 +124,8 @@ static int __init rtctimer_init(void)
 
 	if (rtctimer_freq < 2 || rtctimer_freq > 8192 ||
 	    (rtctimer_freq & (rtctimer_freq - 1)) != 0) {
-		snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n", rtctimer_freq);
+		snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n",
+			   rtctimer_freq);
 		return -EINVAL;
 	}
 
@@ -133,6 +134,7 @@ static int __init rtctimer_init(void)
 	if (err < 0)
 		return err;
 
+	timer->module = THIS_MODULE;
 	strcpy(timer->name, "RTC timer");
 	timer->hw = rtc_hw;
 	timer->hw.resolution = NANO_SEC / rtctimer_freq;
diff --git a/sound/core/timer.c b/sound/core/timer.c
index b02681eaea7..c8496c7b8df 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -113,7 +113,7 @@ static snd_timer_instance_t *snd_timer_instance_new(char *owner, snd_timer_t *ti
 	INIT_LIST_HEAD(&timeri->slave_active_head);
 
 	timeri->timer = timer;
-	if (timer && timer->card && !try_module_get(timer->card->module)) {
+	if (timer && !try_module_get(timer->module)) {
 		kfree(timeri->owner);
 		kfree(timeri);
 		return NULL;
@@ -363,8 +363,8 @@ int snd_timer_close(snd_timer_instance_t * timeri)
 		timeri->private_free(timeri);
 	kfree(timeri->owner);
 	kfree(timeri);
-	if (timer && timer->card)
-		module_put(timer->card->module);
+	if (timer)
+		module_put(timer->module);
 	return 0;
 }
 
@@ -787,6 +787,7 @@ int snd_timer_new(snd_card_t *card, char *id, snd_timer_id_t *tid, snd_timer_t *
 	spin_lock_init(&timer->lock);
 	tasklet_init(&timer->task_queue, snd_timer_tasklet, (unsigned long)timer);
 	if (card != NULL) {
+		timer->module = card->module;
 		if ((err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops)) < 0) {
 			snd_timer_free(timer);
 			return err;