commit de24214d0c8e78134875752619f99b9e5824c196
author Clemens Ladisch <clemens@ladisch.de> Wed Oct 12 17:12:31 2005 +0200
committer Jaroslav Kysela <perex@suse.cz> Fri Nov 04 13:18:43 2005 +0100
tree 147f8cdcf5dfb3be2d95409f7ac44af101d2e0a5
parent 2fd43d1159d22395aae01836c4b13ee5265a9b6b

[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>

include/sound/timer.h

diff --git a/include/sound/timer.h b/include/sound/timer.h
index 1898511..b55f38a 100644
--- a/include/sound/timer.h
+++ b/include/sound/timer.h
@@ -88,6 +88,7 @@
 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];

sound/core/rtctimer.c

diff --git a/sound/core/rtctimer.c b/sound/core/rtctimer.c
index 8762ff8..c3c1856 100644
--- a/sound/core/rtctimer.c
+++ b/sound/core/rtctimer.c
@@ -124,7 +124,8 @@
 
 	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 @@
 	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;

sound/core/timer.c

diff --git a/sound/core/timer.c b/sound/core/timer.c
index b02681e..c8496c7 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -113,7 +113,7 @@
 	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 @@
 		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 @@
 	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;