Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1901 insertions, 0 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
new file mode 100644
index 00000000000..fa762ca439b
--- /dev/null
+++ b/sound/core/timer.c
@@ -0,0 +1,1901 @@
+/*
+ *  Timers abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <sound/driver.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/moduleparam.h>
+#include <sound/core.h>
+#include <sound/timer.h>
+#include <sound/control.h>
+#include <sound/info.h>
+#include <sound/minors.h>
+#include <sound/initval.h>
+#include <linux/kmod.h>
+#ifdef CONFIG_KERNELD
+#include <linux/kerneld.h>
+#endif
+
+#if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
+#define DEFAULT_TIMER_LIMIT 3
+#elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
+#define DEFAULT_TIMER_LIMIT 2
+#else
+#define DEFAULT_TIMER_LIMIT 1
+#endif
+
+static int timer_limit = DEFAULT_TIMER_LIMIT;
+MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA timer interface");
+MODULE_LICENSE("GPL");
+module_param(timer_limit, int, 0444);
+MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
+
+typedef struct {
+	snd_timer_instance_t *timeri;
+	int tread;			/* enhanced read with timestamps and events */
+	unsigned long ticks;
+	unsigned long overrun;
+	int qhead;
+	int qtail;
+	int qused;
+	int queue_size;
+	snd_timer_read_t *queue;
+	snd_timer_tread_t *tqueue;
+	spinlock_t qlock;
+	unsigned long last_resolution;
+	unsigned int filter;
+	struct timespec tstamp;		/* trigger tstamp */
+	wait_queue_head_t qchange_sleep;
+	struct fasync_struct *fasync;
+} snd_timer_user_t;
+
+/* list of timers */
+static LIST_HEAD(snd_timer_list);
+
+/* list of slave instances */
+static LIST_HEAD(snd_timer_slave_list);
+
+/* lock for slave active lists */
+static DEFINE_SPINLOCK(slave_active_lock);
+
+static DECLARE_MUTEX(register_mutex);
+
+static int snd_timer_free(snd_timer_t *timer);
+static int snd_timer_dev_free(snd_device_t *device);
+static int snd_timer_dev_register(snd_device_t *device);
+static int snd_timer_dev_unregister(snd_device_t *device);
+
+static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left);
+
+/*
+ * create a timer instance with the given owner string.
+ * when timer is not NULL, increments the module counter
+ */
+static snd_timer_instance_t *snd_timer_instance_new(char *owner, snd_timer_t *timer)
+{
+	snd_timer_instance_t *timeri;
+	timeri = kcalloc(1, sizeof(*timeri), GFP_KERNEL);
+	if (timeri == NULL)
+		return NULL;
+	timeri->owner = snd_kmalloc_strdup(owner, GFP_KERNEL);
+	if (! timeri->owner) {
+		kfree(timeri);
+		return NULL;
+	}
+	INIT_LIST_HEAD(&timeri->open_list);
+	INIT_LIST_HEAD(&timeri->active_list);
+	INIT_LIST_HEAD(&timeri->ack_list);
+	INIT_LIST_HEAD(&timeri->slave_list_head);
+	INIT_LIST_HEAD(&timeri->slave_active_head);
+
+	timeri->timer = timer;
+	if (timer && timer->card && !try_module_get(timer->card->module)) {
+		kfree(timeri->owner);
+		kfree(timeri);
+		return NULL;
+	}
+
+	return timeri;
+}
+
+/*
+ * find a timer instance from the given timer id
+ */
+static snd_timer_t *snd_timer_find(snd_timer_id_t *tid)
+{
+	snd_timer_t *timer = NULL;
+	struct list_head *p;
+
+	list_for_each(p, &snd_timer_list) {
+		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+
+		if (timer->tmr_class != tid->dev_class)
+			continue;
+		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
+		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
+		    (timer->card == NULL ||
+		     timer->card->number != tid->card))
+			continue;
+		if (timer->tmr_device != tid->device)
+			continue;
+		if (timer->tmr_subdevice != tid->subdevice)
+			continue;
+		return timer;
+	}
+	return NULL;
+}
+
+#ifdef CONFIG_KMOD
+
+static void snd_timer_request(snd_timer_id_t *tid)
+{
+	if (! current->fs->root)
+		return;
+	switch (tid->dev_class) {
+	case SNDRV_TIMER_CLASS_GLOBAL:
+		if (tid->device < timer_limit)
+			request_module("snd-timer-%i", tid->device);
+		break;
+	case SNDRV_TIMER_CLASS_CARD:
+	case SNDRV_TIMER_CLASS_PCM:
+		if (tid->card < snd_ecards_limit)
+			request_module("snd-card-%i", tid->card);
+		break;
+	default:
+		break;
+	}
+}
+
+#endif
+
+/*
+ * look for a master instance matching with the slave id of the given slave.
+ * when found, relink the open_link of the slave.
+ *
+ * call this with register_mutex down.
+ */
+static void snd_timer_check_slave(snd_timer_instance_t *slave)
+{
+	snd_timer_t *timer;
+	snd_timer_instance_t *master;
+	struct list_head *p, *q;
+
+	/* FIXME: it's really dumb to look up all entries.. */
+	list_for_each(p, &snd_timer_list) {
+		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+		list_for_each(q, &timer->open_list_head) {
+			master = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
+			if (slave->slave_class == master->slave_class &&
+			    slave->slave_id == master->slave_id) {
+				list_del(&slave->open_list);
+				list_add_tail(&slave->open_list, &master->slave_list_head);
+				spin_lock_irq(&slave_active_lock);
+				slave->master = master;
+				slave->timer = master->timer;
+				spin_unlock_irq(&slave_active_lock);
+				return;
+			}
+		}
+	}
+}
+
+/*
+ * look for slave instances matching with the slave id of the given master.
+ * when found, relink the open_link of slaves.
+ *
+ * call this with register_mutex down.
+ */
+static void snd_timer_check_master(snd_timer_instance_t *master)
+{
+	snd_timer_instance_t *slave;
+	struct list_head *p, *n;
+
+	/* check all pending slaves */
+	list_for_each_safe(p, n, &snd_timer_slave_list) {
+		slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
+		if (slave->slave_class == master->slave_class &&
+		    slave->slave_id == master->slave_id) {
+			list_del(p);
+			list_add_tail(p, &master->slave_list_head);
+			spin_lock_irq(&slave_active_lock);
+			slave->master = master;
+			slave->timer = master->timer;
+			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
+				list_add_tail(&slave->active_list, &master->slave_active_head);
+			spin_unlock_irq(&slave_active_lock);
+		}
+	}
+}
+
+/*
+ * open a timer instance
+ * when opening a master, the slave id must be here given.
+ */
+int snd_timer_open(snd_timer_instance_t **ti,
+		   char *owner, snd_timer_id_t *tid,
+		   unsigned int slave_id)
+{
+	snd_timer_t *timer;
+	snd_timer_instance_t *timeri = NULL;
+	
+	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
+		/* open a slave instance */
+		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
+		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
+			snd_printd("invalid slave class %i\n", tid->dev_sclass);
+			return -EINVAL;
+		}
+		down(&register_mutex);
+		timeri = snd_timer_instance_new(owner, NULL);
+		timeri->slave_class = tid->dev_sclass;
+		timeri->slave_id = tid->device;
+		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
+		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
+		snd_timer_check_slave(timeri);
+		up(&register_mutex);
+		*ti = timeri;
+		return 0;
+	}
+
+	/* open a master instance */
+	down(&register_mutex);
+	timer = snd_timer_find(tid);
+#ifdef CONFIG_KMOD
+	if (timer == NULL) {
+		up(&register_mutex);
+		snd_timer_request(tid);
+		down(&register_mutex);
+		timer = snd_timer_find(tid);
+	}
+#endif
+	if (timer) {
+		if (!list_empty(&timer->open_list_head)) {
+			timeri = (snd_timer_instance_t *)list_entry(timer->open_list_head.next, snd_timer_instance_t, open_list);
+			if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
+				up(&register_mutex);
+				return -EBUSY;
+			}
+		}
+		timeri = snd_timer_instance_new(owner, timer);
+		if (timeri) {
+			timeri->slave_class = tid->dev_sclass;
+			timeri->slave_id = slave_id;
+			if (list_empty(&timer->open_list_head) && timer->hw.open)
+				timer->hw.open(timer);
+			list_add_tail(&timeri->open_list, &timer->open_list_head);
+			snd_timer_check_master(timeri);
+		}
+	} else {
+		up(&register_mutex);
+		return -ENODEV;
+	}
+	up(&register_mutex);
+	*ti = timeri;
+	return 0;
+}
+
+static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event);
+
+/*
+ * close a timer instance
+ */
+int snd_timer_close(snd_timer_instance_t * timeri)
+{
+	snd_timer_t *timer = NULL;
+	struct list_head *p, *n;
+	snd_timer_instance_t *slave;
+
+	snd_assert(timeri != NULL, return -ENXIO);
+
+	/* force to stop the timer */
+	snd_timer_stop(timeri);
+
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
+		/* wait, until the active callback is finished */
+		spin_lock_irq(&slave_active_lock);
+		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
+			spin_unlock_irq(&slave_active_lock);
+			udelay(10);
+			spin_lock_irq(&slave_active_lock);
+		}
+		spin_unlock_irq(&slave_active_lock);
+		down(&register_mutex);
+		list_del(&timeri->open_list);
+		up(&register_mutex);
+	} else {
+		timer = timeri->timer;
+		/* wait, until the active callback is finished */
+		spin_lock_irq(&timer->lock);
+		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
+			spin_unlock_irq(&timer->lock);
+			udelay(10);
+			spin_lock_irq(&timer->lock);
+		}
+		spin_unlock_irq(&timer->lock);
+		down(&register_mutex);
+		list_del(&timeri->open_list);
+		if (timer && list_empty(&timer->open_list_head) && timer->hw.close)
+			timer->hw.close(timer);
+		/* remove slave links */
+		list_for_each_safe(p, n, &timeri->slave_list_head) {
+			slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
+			spin_lock_irq(&slave_active_lock);
+			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
+			list_del(p);
+			list_add_tail(p, &snd_timer_slave_list);
+			slave->master = NULL;
+			slave->timer = NULL;
+			spin_unlock_irq(&slave_active_lock);
+		}
+		up(&register_mutex);
+	}
+	if (timeri->private_free)
+		timeri->private_free(timeri);
+	kfree(timeri->owner);
+	kfree(timeri);
+	if (timer && timer->card)
+		module_put(timer->card->module);
+	return 0;
+}
+
+unsigned long snd_timer_resolution(snd_timer_instance_t * timeri)
+{
+	snd_timer_t * timer;
+
+	if (timeri == NULL)
+		return 0;
+	if ((timer = timeri->timer) != NULL) {
+		if (timer->hw.c_resolution)
+			return timer->hw.c_resolution(timer);
+		return timer->hw.resolution;
+	}
+	return 0;
+}
+
+static void snd_timer_notify1(snd_timer_instance_t *ti, enum sndrv_timer_event event)
+{
+	snd_timer_t *timer;
+	unsigned long flags;
+	unsigned long resolution = 0;
+	snd_timer_instance_t *ts;
+	struct list_head *n;
+	struct timespec tstamp;
+
+	snd_timestamp_now(&tstamp, 1);
+	snd_assert(event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE, return);
+	if (event == SNDRV_TIMER_EVENT_START || event == SNDRV_TIMER_EVENT_CONTINUE)
+		resolution = snd_timer_resolution(ti);
+	if (ti->ccallback)
+		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
+	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return;
+	timer = ti->timer;
+	if (timer == NULL)
+		return;
+	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		return;
+	spin_lock_irqsave(&timer->lock, flags);
+	list_for_each(n, &ti->slave_active_head) {
+		ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
+		if (ts->ccallback)
+			ts->ccallback(ti, event + 100, &tstamp, resolution);
+	}
+	spin_unlock_irqrestore(&timer->lock, flags);
+}
+
+static int snd_timer_start1(snd_timer_t *timer, snd_timer_instance_t *timeri, unsigned long sticks)
+{
+	list_del(&timeri->active_list);
+	list_add_tail(&timeri->active_list, &timer->active_list_head);
+	if (timer->running) {
+		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			goto __start_now;
+		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
+		timeri->flags |= SNDRV_TIMER_IFLG_START;
+		return 1;	/* delayed start */
+	} else {
+		timer->sticks = sticks;
+		timer->hw.start(timer);
+	      __start_now:
+		timer->running++;
+		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
+		return 0;
+	}
+}
+
+static int snd_timer_start_slave(snd_timer_instance_t *timeri)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&slave_active_lock, flags);
+	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
+	if (timeri->master)
+		list_add_tail(&timeri->active_list, &timeri->master->slave_active_head);
+	spin_unlock_irqrestore(&slave_active_lock, flags);
+	return 1; /* delayed start */
+}
+
+/*
+ *  start the timer instance
+ */ 
+int snd_timer_start(snd_timer_instance_t * timeri, unsigned int ticks)
+{
+	snd_timer_t *timer;
+	int result = -EINVAL;
+	unsigned long flags;
+
+	if (timeri == NULL || ticks < 1)
+		return -EINVAL;
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
+		result = snd_timer_start_slave(timeri);
+		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
+		return result;
+	}
+	timer = timeri->timer;
+	if (timer == NULL)
+		return -EINVAL;
+	spin_lock_irqsave(&timer->lock, flags);
+	timeri->ticks = timeri->cticks = ticks;
+	timeri->pticks = 0;
+	result = snd_timer_start1(timer, timeri, ticks);
+	spin_unlock_irqrestore(&timer->lock, flags);
+	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
+	return result;
+}
+
+static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event)
+{
+	snd_timer_t *timer;
+	unsigned long flags;
+
+	snd_assert(timeri != NULL, return -ENXIO);
+
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
+		if (!keep_flag) {
+			spin_lock_irqsave(&slave_active_lock, flags);
+			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
+			spin_unlock_irqrestore(&slave_active_lock, flags);
+		}
+		goto __end;
+	}
+	timer = timeri->timer;
+	if (!timer)
+		return -EINVAL;
+	spin_lock_irqsave(&timer->lock, flags);
+	list_del_init(&timeri->ack_list);
+	list_del_init(&timeri->active_list);
+	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
+	    !(--timer->running)) {
+		timer->hw.stop(timer);
+		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
+			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
+			snd_timer_reschedule(timer, 0);
+			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
+				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
+				timer->hw.start(timer);
+			}
+		}
+	}
+	if (!keep_flag)
+		timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING|SNDRV_TIMER_IFLG_START);
+	spin_unlock_irqrestore(&timer->lock, flags);
+      __end:
+	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
+		snd_timer_notify1(timeri, event);
+	return 0;
+}
+
+/*
+ * stop the timer instance.
+ *
+ * do not call this from the timer callback!
+ */
+int snd_timer_stop(snd_timer_instance_t * timeri)
+{
+	snd_timer_t *timer;
+	unsigned long flags;
+	int err;
+
+	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
+	if (err < 0)
+		return err;
+	timer = timeri->timer;
+	spin_lock_irqsave(&timer->lock, flags);
+	timeri->cticks = timeri->ticks;
+	timeri->pticks = 0;
+	spin_unlock_irqrestore(&timer->lock, flags);
+	return 0;
+}
+
+/*
+ * start again..  the tick is kept.
+ */
+int snd_timer_continue(snd_timer_instance_t * timeri)
+{
+	snd_timer_t *timer;
+	int result = -EINVAL;
+	unsigned long flags;
+
+	if (timeri == NULL)
+		return result;
+	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+		return snd_timer_start_slave(timeri);
+	timer = timeri->timer;
+	if (! timer)
+		return -EINVAL;
+	spin_lock_irqsave(&timer->lock, flags);
+	if (!timeri->cticks)
+		timeri->cticks = 1;
+	timeri->pticks = 0;
+	result = snd_timer_start1(timer, timeri, timer->sticks);
+	spin_unlock_irqrestore(&timer->lock, flags);
+	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
+	return result;
+}
+
+/*
+ * pause.. remember the ticks left
+ */
+int snd_timer_pause(snd_timer_instance_t * timeri)
+{
+	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
+}
+
+/*
+ * reschedule the timer
+ *
+ * start pending instances and check the scheduling ticks.
+ * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
+ */
+static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left)
+{
+	snd_timer_instance_t *ti;
+	unsigned long ticks = ~0UL;
+	struct list_head *p;
+
+	list_for_each(p, &timer->active_list_head) {
+		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
+		if (ti->flags & SNDRV_TIMER_IFLG_START) {
+			ti->flags &= ~SNDRV_TIMER_IFLG_START;
+			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
+			timer->running++;
+		}
+		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
+			if (ticks > ti->cticks)
+				ticks = ti->cticks;
+		}
+	}
+	if (ticks == ~0UL) {
+		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
+		return;
+	}
+	if (ticks > timer->hw.ticks)
+		ticks = timer->hw.ticks;
+	if (ticks_left != ticks)
+		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
+	timer->sticks = ticks;
+}
+
+/*
+ * timer tasklet
+ *
+ */
+static void snd_timer_tasklet(unsigned long arg)
+{
+	snd_timer_t *timer = (snd_timer_t *) arg;
+	snd_timer_instance_t *ti;
+	struct list_head *p;
+	unsigned long resolution, ticks;
+
+	spin_lock(&timer->lock);
+	/* now process all callbacks */
+	while (!list_empty(&timer->sack_list_head)) {
+		p = timer->sack_list_head.next;		/* get first item */
+		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
+
+		/* remove from ack_list and make empty */
+		list_del_init(p);
+		
+		ticks = ti->pticks;
+		ti->pticks = 0;
+		resolution = ti->resolution;
+
+		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
+		spin_unlock(&timer->lock);
+		if (ti->callback)
+			ti->callback(ti, resolution, ticks);
+		spin_lock(&timer->lock);
+		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
+	}
+	spin_unlock(&timer->lock);
+}
+
+/*
+ * timer interrupt
+ *
+ * ticks_left is usually equal to timer->sticks.
+ *
+ */
+void snd_timer_interrupt(snd_timer_t * timer, unsigned long ticks_left)
+{
+	snd_timer_instance_t *ti, *ts;
+	unsigned long resolution, ticks;
+	struct list_head *p, *q, *n;
+	int use_tasklet = 0;
+
+	if (timer == NULL)
+		return;
+
+	spin_lock(&timer->lock);
+
+	/* remember the current resolution */
+	if (timer->hw.c_resolution)
+		resolution = timer->hw.c_resolution(timer);
+	else
+		resolution = timer->hw.resolution;
+
+	/* loop for all active instances
+	 * here we cannot use list_for_each because the active_list of a processed
+	 * instance is relinked to done_list_head before callback is called.
+	 */
+	list_for_each_safe(p, n, &timer->active_list_head) {
+		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
+		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
+			continue;
+		ti->pticks += ticks_left;
+		ti->resolution = resolution;
+		if (ti->cticks < ticks_left)
+			ti->cticks = 0;
+		else
+			ti->cticks -= ticks_left;
+		if (ti->cticks) /* not expired */
+			continue;
+		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
+			ti->cticks = ti->ticks;
+		} else {
+			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
+			if (--timer->running)
+				list_del(p);
+		}
+		if (list_empty(&ti->ack_list)) {
+			if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
+			    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
+				list_add_tail(&ti->ack_list, &timer->ack_list_head);
+			} else {
+				list_add_tail(&ti->ack_list, &timer->sack_list_head);
+			}
+		}
+		list_for_each(q, &ti->slave_active_head) {
+			ts = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, active_list);
+			ts->pticks = ti->pticks;
+			ts->resolution = resolution;
+			if (list_empty(&ts->ack_list)) {
+				if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
+				    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
+					list_add_tail(&ts->ack_list, &timer->ack_list_head);
+				} else {
+					list_add_tail(&ts->ack_list, &timer->sack_list_head);
+				}
+			}
+		}
+	}
+	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
+		snd_timer_reschedule(timer, ticks_left);
+	if (timer->running) {
+		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
+			timer->hw.stop(timer);
+			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
+		}
+		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
+		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
+			/* restart timer */
+			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
+			timer->hw.start(timer);
+		}
+	} else {
+		timer->hw.stop(timer);
+	}
+
+	/* now process all fast callbacks */
+	while (!list_empty(&timer->ack_list_head)) {
+		p = timer->ack_list_head.next;		/* get first item */
+		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
+		
+		/* remove from ack_list and make empty */
+		list_del_init(p);
+		
+		ticks = ti->pticks;
+		ti->pticks = 0;
+
+		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
+		spin_unlock(&timer->lock);
+		if (ti->callback)
+			ti->callback(ti, resolution, ticks);
+		spin_lock(&timer->lock);
+		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
+	}
+
+	/* do we have any slow callbacks? */
+	use_tasklet = !list_empty(&timer->sack_list_head);
+	spin_unlock(&timer->lock);
+
+	if (use_tasklet)
+		tasklet_hi_schedule(&timer->task_queue);
+}
+
+/*
+
+ */
+
+int snd_timer_new(snd_card_t *card, char *id, snd_timer_id_t *tid, snd_timer_t ** rtimer)
+{
+	snd_timer_t *timer;
+	int err;
+	static snd_device_ops_t ops = {
+		.dev_free = snd_timer_dev_free,
+		.dev_register = snd_timer_dev_register,
+		.dev_unregister = snd_timer_dev_unregister
+	};
+
+	snd_assert(tid != NULL, return -EINVAL);
+	snd_assert(rtimer != NULL, return -EINVAL);
+	*rtimer = NULL;
+	timer = kcalloc(1, sizeof(*timer), GFP_KERNEL);
+	if (timer == NULL)
+		return -ENOMEM;
+	timer->tmr_class = tid->dev_class;
+	timer->card = card;
+	timer->tmr_device = tid->device;
+	timer->tmr_subdevice = tid->subdevice;
+	if (id)
+		strlcpy(timer->id, id, sizeof(timer->id));
+	INIT_LIST_HEAD(&timer->device_list);
+	INIT_LIST_HEAD(&timer->open_list_head);
+	INIT_LIST_HEAD(&timer->active_list_head);
+	INIT_LIST_HEAD(&timer->ack_list_head);
+	INIT_LIST_HEAD(&timer->sack_list_head);
+	spin_lock_init(&timer->lock);
+	tasklet_init(&timer->task_queue, snd_timer_tasklet, (unsigned long)timer);
+	if (card != NULL) {
+		if ((err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops)) < 0) {
+			snd_timer_free(timer);
+			return err;
+		}
+	}
+	*rtimer = timer;
+	return 0;
+}
+
+static int snd_timer_free(snd_timer_t *timer)
+{
+	snd_assert(timer != NULL, return -ENXIO);
+	if (timer->private_free)
+		timer->private_free(timer);
+	kfree(timer);
+	return 0;
+}
+
+int snd_timer_dev_free(snd_device_t *device)
+{
+	snd_timer_t *timer = device->device_data;
+	return snd_timer_free(timer);
+}
+
+int snd_timer_dev_register(snd_device_t *dev)
+{
+	snd_timer_t *timer = dev->device_data;
+	snd_timer_t *timer1;
+	struct list_head *p;
+
+	snd_assert(timer != NULL && timer->hw.start != NULL && timer->hw.stop != NULL, return -ENXIO);
+	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
+	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
+	    	return -EINVAL;
+
+	down(&register_mutex);
+	list_for_each(p, &snd_timer_list) {
+		timer1 = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+		if (timer1->tmr_class > timer->tmr_class)
+			break;
+		if (timer1->tmr_class < timer->tmr_class)
+			continue;
+		if (timer1->card && timer->card) {
+			if (timer1->card->number > timer->card->number)
+				break;
+			if (timer1->card->number < timer->card->number)
+				continue;
+		}
+		if (timer1->tmr_device > timer->tmr_device)
+			break;
+		if (timer1->tmr_device < timer->tmr_device)
+			continue;
+		if (timer1->tmr_subdevice > timer->tmr_subdevice)
+			break;
+		if (timer1->tmr_subdevice < timer->tmr_subdevice)
+			continue;
+		/* conflicts.. */
+		up(&register_mutex);
+		return -EBUSY;
+	}
+	list_add_tail(&timer->device_list, p);
+	up(&register_mutex);
+	return 0;
+}
+
+int snd_timer_unregister(snd_timer_t *timer)
+{
+	struct list_head *p, *n;
+	snd_timer_instance_t *ti;
+
+	snd_assert(timer != NULL, return -ENXIO);
+	down(&register_mutex);
+	if (! list_empty(&timer->open_list_head)) {
+		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
+		list_for_each_safe(p, n, &timer->open_list_head) {
+			list_del_init(p);
+			ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
+			ti->timer = NULL;
+		}
+	}
+	list_del(&timer->device_list);
+	up(&register_mutex);
+	return snd_timer_free(timer);
+}
+
+static int snd_timer_dev_unregister(snd_device_t *device)
+{
+	snd_timer_t *timer = device->device_data;
+	return snd_timer_unregister(timer);
+}
+
+void snd_timer_notify(snd_timer_t *timer, enum sndrv_timer_event event, struct timespec *tstamp)
+{
+	unsigned long flags;
+	unsigned long resolution = 0;
+	snd_timer_instance_t *ti, *ts;
+	struct list_head *p, *n;
+
+	snd_runtime_check(timer->hw.flags & SNDRV_TIMER_HW_SLAVE, return);	
+	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART && event <= SNDRV_TIMER_EVENT_MPAUSE, return);
+	spin_lock_irqsave(&timer->lock, flags);
+	if (event == SNDRV_TIMER_EVENT_MSTART || event == SNDRV_TIMER_EVENT_MCONTINUE) {
+		if (timer->hw.c_resolution)
+			resolution = timer->hw.c_resolution(timer);
+		else
+			resolution = timer->hw.resolution;
+	}
+	list_for_each(p, &timer->active_list_head) {
+		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
+		if (ti->ccallback)
+			ti->ccallback(ti, event, tstamp, resolution);
+		list_for_each(n, &ti->slave_active_head) {
+			ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
+			if (ts->ccallback)
+				ts->ccallback(ts, event, tstamp, resolution);
+		}
+	}
+	spin_unlock_irqrestore(&timer->lock, flags);
+}
+
+/*
+ * exported functions for global timers
+ */
+int snd_timer_global_new(char *id, int device, snd_timer_t **rtimer)
+{
+	snd_timer_id_t tid;
+	
+	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.card = -1;
+	tid.device = device;
+	tid.subdevice = 0;
+	return snd_timer_new(NULL, id, &tid, rtimer);
+}
+
+int snd_timer_global_free(snd_timer_t *timer)
+{
+	return snd_timer_free(timer);
+}
+
+int snd_timer_global_register(snd_timer_t *timer)
+{
+	snd_device_t dev;
+
+	memset(&dev, 0, sizeof(dev));
+	dev.device_data = timer;
+	return snd_timer_dev_register(&dev);
+}
+
+int snd_timer_global_unregister(snd_timer_t *timer)
+{
+	return snd_timer_unregister(timer);
+}
+
+/* 
+ *  System timer
+ */
+
+struct snd_timer_system_private {
+	struct timer_list tlist;
+	struct timer * timer;
+	unsigned long last_expires;
+	unsigned long last_jiffies;
+	unsigned long correction;
+};
+
+unsigned int snd_timer_system_resolution(void)
+{
+	return 1000000000L / HZ;
+}
+
+static void snd_timer_s_function(unsigned long data)
+{
+	snd_timer_t *timer = (snd_timer_t *)data;
+	struct snd_timer_system_private *priv = timer->private_data;
+	unsigned long jiff = jiffies;
+	if (time_after(jiff, priv->last_expires))
+		priv->correction = (long)jiff - (long)priv->last_expires;
+	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
+}
+
+static int snd_timer_s_start(snd_timer_t * timer)
+{
+	struct snd_timer_system_private *priv;
+	unsigned long njiff;
+
+	priv = (struct snd_timer_system_private *) timer->private_data;
+	njiff = (priv->last_jiffies = jiffies);
+	if (priv->correction > timer->sticks - 1) {
+		priv->correction -= timer->sticks - 1;
+		njiff++;
+	} else {
+		njiff += timer->sticks - priv->correction;
+		priv->correction -= timer->sticks;
+	}
+	priv->last_expires = priv->tlist.expires = njiff;
+	add_timer(&priv->tlist);
+	return 0;
+}
+
+static int snd_timer_s_stop(snd_timer_t * timer)
+{
+	struct snd_timer_system_private *priv;
+	unsigned long jiff;
+
+	priv = (struct snd_timer_system_private *) timer->private_data;
+	del_timer(&priv->tlist);
+	jiff = jiffies;
+	if (time_before(jiff, priv->last_expires))
+		timer->sticks = priv->last_expires - jiff;
+	else
+		timer->sticks = 1;
+	return 0;
+}
+
+static struct _snd_timer_hardware snd_timer_system =
+{
+	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
+	.resolution =	1000000000L / HZ,
+	.ticks =	10000000L,
+	.start =	snd_timer_s_start,
+	.stop =		snd_timer_s_stop
+};
+
+static void snd_timer_free_system(snd_timer_t *timer)
+{
+	kfree(timer->private_data);
+}
+
+static int snd_timer_register_system(void)
+{
+	snd_timer_t *timer;
+	struct snd_timer_system_private *priv;
+	int err;
+
+	if ((err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer)) < 0)
+		return err;
+	strcpy(timer->name, "system timer");
+	timer->hw = snd_timer_system;
+	priv = kcalloc(1, sizeof(*priv), GFP_KERNEL);
+	if (priv == NULL) {
+		snd_timer_free(timer);
+		return -ENOMEM;
+	}
+	init_timer(&priv->tlist);
+	priv->tlist.function = snd_timer_s_function;
+	priv->tlist.data = (unsigned long) timer;
+	timer->private_data = priv;
+	timer->private_free = snd_timer_free_system;
+	return snd_timer_global_register(timer);
+}
+
+/*
+ *  Info interface
+ */
+
+static void snd_timer_proc_read(snd_info_entry_t *entry,
+				snd_info_buffer_t * buffer)
+{
+	unsigned long flags;
+	snd_timer_t *timer;
+	snd_timer_instance_t *ti;
+	struct list_head *p, *q;
+
+	down(&register_mutex);
+	list_for_each(p, &snd_timer_list) {
+		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+		switch (timer->tmr_class) {
+		case SNDRV_TIMER_CLASS_GLOBAL:
+			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
+			break;
+		case SNDRV_TIMER_CLASS_CARD:
+			snd_iprintf(buffer, "C%i-%i: ", timer->card->number, timer->tmr_device);
+			break;
+		case SNDRV_TIMER_CLASS_PCM:
+			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number, timer->tmr_device, timer->tmr_subdevice);
+			break;
+		default:
+			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class, timer->card ? timer->card->number : -1, timer->tmr_device, timer->tmr_subdevice);
+		}
+		snd_iprintf(buffer, "%s :", timer->name);
+		if (timer->hw.resolution)
+			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)", timer->hw.resolution / 1000, timer->hw.resolution % 1000, timer->hw.ticks);
+		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			snd_iprintf(buffer, " SLAVE");
+		snd_iprintf(buffer, "\n");
+		spin_lock_irqsave(&timer->lock, flags);
+		list_for_each(q, &timer->open_list_head) {
+			ti = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
+			snd_iprintf(buffer, "  Client %s : %s : lost interrupts %li\n",
+					ti->owner ? ti->owner : "unknown",
+					ti->flags & (SNDRV_TIMER_IFLG_START|SNDRV_TIMER_IFLG_RUNNING) ? "running" : "stopped",
+					ti->lost);
+		}
+		spin_unlock_irqrestore(&timer->lock, flags);
+	}
+	up(&register_mutex);
+}
+
+/*
+ *  USER SPACE interface
+ */
+
+static void snd_timer_user_interrupt(snd_timer_instance_t *timeri,
+				     unsigned long resolution,
+				     unsigned long ticks)
+{
+	snd_timer_user_t *tu = timeri->callback_data;
+	snd_timer_read_t *r;
+	int prev;
+	
+	spin_lock(&tu->qlock);
+	if (tu->qused > 0) {
+		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
+		r = &tu->queue[prev];
+		if (r->resolution == resolution) {
+			r->ticks += ticks;
+			goto __wake;
+		}
+	}
+	if (tu->qused >= tu->queue_size) {
+		tu->overrun++;
+	} else {
+		r = &tu->queue[tu->qtail++];
+		tu->qtail %= tu->queue_size;
+		r->resolution = resolution;
+		r->ticks = ticks;
+		tu->qused++;
+	}
+      __wake:
+	spin_unlock(&tu->qlock);
+	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static void snd_timer_user_append_to_tqueue(snd_timer_user_t *tu, snd_timer_tread_t *tread)
+{
+	if (tu->qused >= tu->queue_size) {
+		tu->overrun++;
+	} else {
+		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
+		tu->qtail %= tu->queue_size;
+		tu->qused++;
+	}
+}
+
+static void snd_timer_user_ccallback(snd_timer_instance_t *timeri,
+				     enum sndrv_timer_event event,
+				     struct timespec *tstamp,
+				     unsigned long resolution)
+{
+	snd_timer_user_t *tu = timeri->callback_data;
+	snd_timer_tread_t r1;
+
+	if (event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE)
+		tu->tstamp = *tstamp;
+	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
+		return;
+	r1.event = event;
+	r1.tstamp = *tstamp;
+	r1.val = resolution;
+	spin_lock(&tu->qlock);
+	snd_timer_user_append_to_tqueue(tu, &r1);
+	spin_unlock(&tu->qlock);
+	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static void snd_timer_user_tinterrupt(snd_timer_instance_t *timeri,
+				      unsigned long resolution,
+				      unsigned long ticks)
+{
+	snd_timer_user_t *tu = timeri->callback_data;
+	snd_timer_tread_t *r, r1;
+	struct timespec tstamp;
+	int prev, append = 0;
+
+	snd_timestamp_zero(&tstamp);
+	spin_lock(&tu->qlock);
+	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION)|(1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
+		spin_unlock(&tu->qlock);
+		return;
+	}
+	if (tu->last_resolution != resolution || ticks > 0)
+		snd_timestamp_now(&tstamp, 1);
+	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) && tu->last_resolution != resolution) {
+		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
+		r1.tstamp = tstamp;
+		r1.val = resolution;
+		snd_timer_user_append_to_tqueue(tu, &r1);
+		tu->last_resolution = resolution;
+		append++;
+	}
+	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
+		goto __wake;
+	if (ticks == 0)
+		goto __wake;
+	if (tu->qused > 0) {
+		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
+		r = &tu->tqueue[prev];
+		if (r->event == SNDRV_TIMER_EVENT_TICK) {
+			r->tstamp = tstamp;
+			r->val += ticks;
+			append++;
+			goto __wake;
+		}
+	}
+	r1.event = SNDRV_TIMER_EVENT_TICK;
+	r1.tstamp = tstamp;
+	r1.val = ticks;
+	snd_timer_user_append_to_tqueue(tu, &r1);
+	append++;
+      __wake:
+	spin_unlock(&tu->qlock);
+	if (append == 0)
+		return;
+	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
+	wake_up(&tu->qchange_sleep);
+}
+
+static int snd_timer_user_open(struct inode *inode, struct file *file)
+{
+	snd_timer_user_t *tu;
+	
+	tu = kcalloc(1, sizeof(*tu), GFP_KERNEL);
+	if (tu == NULL)
+		return -ENOMEM;
+	spin_lock_init(&tu->qlock);
+	init_waitqueue_head(&tu->qchange_sleep);
+	tu->ticks = 1;
+	tu->queue_size = 128;
+	tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
+	if (tu->queue == NULL) {
+		kfree(tu);
+		return -ENOMEM;
+	}
+	file->private_data = tu;
+	return 0;
+}
+
+static int snd_timer_user_release(struct inode *inode, struct file *file)
+{
+	snd_timer_user_t *tu;
+
+	if (file->private_data) {
+		tu = file->private_data;
+		file->private_data = NULL;
+		fasync_helper(-1, file, 0, &tu->fasync);
+		if (tu->timeri)
+			snd_timer_close(tu->timeri);
+		kfree(tu->queue);
+		kfree(tu->tqueue);
+		kfree(tu);
+	}
+	return 0;
+}
+
+static void snd_timer_user_zero_id(snd_timer_id_t *id)
+{
+	id->dev_class = SNDRV_TIMER_CLASS_NONE;
+	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	id->card = -1;
+	id->device = -1;
+	id->subdevice = -1;
+}
+
+static void snd_timer_user_copy_id(snd_timer_id_t *id, snd_timer_t *timer)
+{
+	id->dev_class = timer->tmr_class;
+	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	id->card = timer->card ? timer->card->number : -1;
+	id->device = timer->tmr_device;
+	id->subdevice = timer->tmr_subdevice;
+}
+
+static int snd_timer_user_next_device(snd_timer_id_t __user *_tid)
+{
+	snd_timer_id_t id;
+	snd_timer_t *timer;
+	struct list_head *p;
+	
+	if (copy_from_user(&id, _tid, sizeof(id)))
+		return -EFAULT;
+	down(&register_mutex);
+	if (id.dev_class < 0) {		/* first item */
+		if (list_empty(&snd_timer_list))
+			snd_timer_user_zero_id(&id);
+		else {
+			timer = (snd_timer_t *)list_entry(snd_timer_list.next, snd_timer_t, device_list);
+			snd_timer_user_copy_id(&id, timer);
+		}
+	} else {
+		switch (id.dev_class) {
+		case SNDRV_TIMER_CLASS_GLOBAL:
+			id.device = id.device < 0 ? 0 : id.device + 1;
+			list_for_each(p, &snd_timer_list) {
+				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_device >= id.device) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+			}
+			if (p == &snd_timer_list)
+				snd_timer_user_zero_id(&id);
+			break;
+		case SNDRV_TIMER_CLASS_CARD:
+		case SNDRV_TIMER_CLASS_PCM:
+			if (id.card < 0) {
+				id.card = 0;
+			} else {
+				if (id.card < 0) {
+					id.card = 0;
+				} else {
+					if (id.device < 0) {
+						id.device = 0;
+					} else {
+						id.subdevice = id.subdevice < 0 ? 0 : id.subdevice + 1;
+					}
+				}
+			}
+			list_for_each(p, &snd_timer_list) {
+				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+				if (timer->tmr_class > id.dev_class) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_class < id.dev_class)
+					continue;
+				if (timer->card->number > id.card) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->card->number < id.card)
+					continue;
+				if (timer->tmr_device > id.device) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_device < id.device)
+					continue;
+				if (timer->tmr_subdevice > id.subdevice) {
+					snd_timer_user_copy_id(&id, timer);
+					break;
+				}
+				if (timer->tmr_subdevice < id.subdevice)
+					continue;
+				snd_timer_user_copy_id(&id, timer);
+				break;
+			}
+			if (p == &snd_timer_list)
+				snd_timer_user_zero_id(&id);
+			break;
+		default:
+			snd_timer_user_zero_id(&id);
+		}
+	}
+	up(&register_mutex);
+	if (copy_to_user(_tid, &id, sizeof(*_tid)))
+		return -EFAULT;
+	return 0;
+} 
+
+static int snd_timer_user_ginfo(struct file *file, snd_timer_ginfo_t __user *_ginfo)
+{
+	snd_timer_ginfo_t *ginfo;
+	snd_timer_id_t tid;
+	snd_timer_t *t;
+	struct list_head *p;
+	int err = 0;
+
+	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
+	if (! ginfo)
+		return -ENOMEM;
+	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
+		kfree(ginfo);
+		return -EFAULT;
+	}
+	tid = ginfo->tid;
+	memset(ginfo, 0, sizeof(*ginfo));
+	ginfo->tid = tid;
+	down(&register_mutex);
+	t = snd_timer_find(&tid);
+	if (t != NULL) {
+		ginfo->card = t->card ? t->card->number : -1;
+		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
+		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
+		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
+		ginfo->resolution = t->hw.resolution;
+		if (t->hw.resolution_min > 0) {
+			ginfo->resolution_min = t->hw.resolution_min;
+			ginfo->resolution_max = t->hw.resolution_max;
+		}
+		list_for_each(p, &t->open_list_head) {
+			ginfo->clients++;
+		}
+	} else {
+		err = -ENODEV;
+	}
+	up(&register_mutex);
+	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
+		err = -EFAULT;
+	kfree(ginfo);
+	return err;
+}
+
+static int snd_timer_user_gparams(struct file *file, snd_timer_gparams_t __user *_gparams)
+{
+	snd_timer_gparams_t gparams;
+	snd_timer_t *t;
+	int err;
+
+	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
+		return -EFAULT;
+	down(&register_mutex);
+	t = snd_timer_find(&gparams.tid);
+	if (t != NULL) {
+		if (list_empty(&t->open_list_head)) {
+			if (t->hw.set_period)
+				err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
+			else
+				err = -ENOSYS;
+		} else {
+			err = -EBUSY;
+		}
+	} else {
+		err = -ENODEV;
+	}
+	up(&register_mutex);
+	return err;
+}
+
+static int snd_timer_user_gstatus(struct file *file, snd_timer_gstatus_t __user *_gstatus)
+{
+	snd_timer_gstatus_t gstatus;
+	snd_timer_id_t tid;
+	snd_timer_t *t;
+	int err = 0;
+
+	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
+		return -EFAULT;
+	tid = gstatus.tid;
+	memset(&gstatus, 0, sizeof(gstatus));
+	gstatus.tid = tid;
+	down(&register_mutex);
+	t = snd_timer_find(&tid);
+	if (t != NULL) {
+		if (t->hw.c_resolution)
+			gstatus.resolution = t->hw.c_resolution(t);
+		else
+			gstatus.resolution = t->hw.resolution;
+		if (t->hw.precise_resolution) {
+			t->hw.precise_resolution(t, &gstatus.resolution_num, &gstatus.resolution_den);
+		} else {
+			gstatus.resolution_num = gstatus.resolution;
+			gstatus.resolution_den = 1000000000uL;
+		}
+	} else {
+		err = -ENODEV;
+	}
+	up(&register_mutex);
+	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
+		err = -EFAULT;
+	return err;
+}
+
+static int snd_timer_user_tselect(struct file *file, snd_timer_select_t __user *_tselect)
+{
+	snd_timer_user_t *tu;
+	snd_timer_select_t tselect;
+	char str[32];
+	int err;
+	
+	tu = file->private_data;
+	if (tu->timeri)
+		snd_timer_close(tu->timeri);
+	if (copy_from_user(&tselect, _tselect, sizeof(tselect)))
+		return -EFAULT;
+	sprintf(str, "application %i", current->pid);
+	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
+		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
+	if ((err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid)) < 0)
+		return err;
+
+	if (tu->queue) {
+		kfree(tu->queue);
+		tu->queue = NULL;
+	}
+	if (tu->tqueue) {
+		kfree(tu->tqueue);
+		tu->tqueue = NULL;
+	}
+	if (tu->tread) {
+		tu->tqueue = (snd_timer_tread_t *)kmalloc(tu->queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
+		if (tu->tqueue == NULL) {
+			snd_timer_close(tu->timeri);
+			return -ENOMEM;
+		}
+	} else {
+		tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
+		if (tu->queue == NULL) {
+			snd_timer_close(tu->timeri);
+			return -ENOMEM;
+		}
+	}
+	
+	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
+	tu->timeri->callback = tu->tread ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
+	tu->timeri->ccallback = snd_timer_user_ccallback;
+	tu->timeri->callback_data = (void *)tu;
+	return 0;
+}
+
+static int snd_timer_user_info(struct file *file, snd_timer_info_t __user *_info)
+{
+	snd_timer_user_t *tu;
+	snd_timer_info_t *info;
+	snd_timer_t *t;
+	int err = 0;
+
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	t = tu->timeri->timer;
+	snd_assert(t != NULL, return -ENXIO);
+
+	info = kcalloc(1, sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	info->card = t->card ? t->card->number : -1;
+	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+		info->flags |= SNDRV_TIMER_FLG_SLAVE;
+	strlcpy(info->id, t->id, sizeof(info->id));
+	strlcpy(info->name, t->name, sizeof(info->name));
+	info->resolution = t->hw.resolution;
+	if (copy_to_user(_info, info, sizeof(*_info)))
+		err = -EFAULT;
+	kfree(info);
+	return err;
+}
+
+static int snd_timer_user_params(struct file *file, snd_timer_params_t __user *_params)
+{
+	snd_timer_user_t *tu;
+	snd_timer_params_t params;
+	snd_timer_t *t;
+	snd_timer_read_t *tr;
+	snd_timer_tread_t *ttr;
+	int err;
+	
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	t = tu->timeri->timer;
+	snd_assert(t != NULL, return -ENXIO);
+	if (copy_from_user(&params, _params, sizeof(params)))
+		return -EFAULT;
+	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
+		err = -EINVAL;
+		goto _end;
+	}
+	if (params.queue_size > 0 && (params.queue_size < 32 || params.queue_size > 1024)) {
+		err = -EINVAL;
+		goto _end;
+	}
+	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
+			      (1<<SNDRV_TIMER_EVENT_TICK)|
+			      (1<<SNDRV_TIMER_EVENT_START)|
+			      (1<<SNDRV_TIMER_EVENT_STOP)|
+			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
+			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
+			      (1<<SNDRV_TIMER_EVENT_MSTART)|
+			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
+			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
+			      (1<<SNDRV_TIMER_EVENT_MPAUSE))) {
+		err = -EINVAL;
+		goto _end;
+	}
+	snd_timer_stop(tu->timeri);
+	spin_lock_irq(&t->lock);
+	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
+			       SNDRV_TIMER_IFLG_EXCLUSIVE|
+			       SNDRV_TIMER_IFLG_EARLY_EVENT);
+	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
+	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
+	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
+		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
+	spin_unlock_irq(&t->lock);
+	if (params.queue_size > 0 && (unsigned int)tu->queue_size != params.queue_size) {
+		if (tu->tread) {
+			ttr = (snd_timer_tread_t *)kmalloc(params.queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
+			if (ttr) {
+				kfree(tu->tqueue);
+				tu->queue_size = params.queue_size;
+				tu->tqueue = ttr;
+			}
+		} else {
+			tr = (snd_timer_read_t *)kmalloc(params.queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
+			if (tr) {
+				kfree(tu->queue);
+				tu->queue_size = params.queue_size;
+				tu->queue = tr;
+			}
+		}
+	}
+	tu->qhead = tu->qtail = tu->qused = 0;
+	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
+		if (tu->tread) {
+			snd_timer_tread_t tread;
+			tread.event = SNDRV_TIMER_EVENT_EARLY;
+			tread.tstamp.tv_sec = 0;
+			tread.tstamp.tv_nsec = 0;
+			tread.val = 0;
+			snd_timer_user_append_to_tqueue(tu, &tread);
+		} else {
+			snd_timer_read_t *r = &tu->queue[0];
+			r->resolution = 0;
+			r->ticks = 0;
+			tu->qused++;
+			tu->qtail++;
+		}
+		
+	}
+	tu->filter = params.filter;
+	tu->ticks = params.ticks;
+	err = 0;
+ _end:
+	if (copy_to_user(_params, &params, sizeof(params)))
+		return -EFAULT;
+	return err;
+}
+
+static int snd_timer_user_status(struct file *file, snd_timer_status_t __user *_status)
+{
+	snd_timer_user_t *tu;
+	snd_timer_status_t status;
+	
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	memset(&status, 0, sizeof(status));
+	status.tstamp = tu->tstamp;
+	status.resolution = snd_timer_resolution(tu->timeri);
+	status.lost = tu->timeri->lost;
+	status.overrun = tu->overrun;
+	spin_lock_irq(&tu->qlock);
+	status.queue = tu->qused;
+	spin_unlock_irq(&tu->qlock);
+	if (copy_to_user(_status, &status, sizeof(status)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_timer_user_start(struct file *file)
+{
+	int err;
+	snd_timer_user_t *tu;
+		
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	snd_timer_stop(tu->timeri);
+	tu->timeri->lost = 0;
+	tu->last_resolution = 0;
+	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
+}
+
+static int snd_timer_user_stop(struct file *file)
+{
+	int err;
+	snd_timer_user_t *tu;
+		
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
+}
+
+static int snd_timer_user_continue(struct file *file)
+{
+	int err;
+	snd_timer_user_t *tu;
+		
+	tu = file->private_data;
+	snd_assert(tu->timeri != NULL, return -ENXIO);
+	tu->timeri->lost = 0;
+	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
+}
+
+static long snd_timer_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	snd_timer_user_t *tu;
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	
+	tu = file->private_data;
+	switch (cmd) {
+	case SNDRV_TIMER_IOCTL_PVERSION:
+		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
+	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
+		return snd_timer_user_next_device(argp);
+	case SNDRV_TIMER_IOCTL_TREAD:
+	{
+		int xarg;
+		
+		if (tu->timeri)		/* too late */
+			return -EBUSY;
+		if (get_user(xarg, p))
+			return -EFAULT;
+		tu->tread = xarg ? 1 : 0;
+		return 0;
+	}
+	case SNDRV_TIMER_IOCTL_GINFO:
+		return snd_timer_user_ginfo(file, argp);
+	case SNDRV_TIMER_IOCTL_GPARAMS:
+		return snd_timer_user_gparams(file, argp);
+	case SNDRV_TIMER_IOCTL_GSTATUS:
+		return snd_timer_user_gstatus(file, argp);
+	case SNDRV_TIMER_IOCTL_SELECT:
+		return snd_timer_user_tselect(file, argp);
+	case SNDRV_TIMER_IOCTL_INFO:
+		return snd_timer_user_info(file, argp);
+	case SNDRV_TIMER_IOCTL_PARAMS:
+		return snd_timer_user_params(file, argp);
+	case SNDRV_TIMER_IOCTL_STATUS:
+		return snd_timer_user_status(file, argp);
+	case SNDRV_TIMER_IOCTL_START:
+		return snd_timer_user_start(file);
+	case SNDRV_TIMER_IOCTL_STOP:
+		return snd_timer_user_stop(file);
+	case SNDRV_TIMER_IOCTL_CONTINUE:
+		return snd_timer_user_continue(file);
+	}
+	return -ENOTTY;
+}
+
+static int snd_timer_user_fasync(int fd, struct file * file, int on)
+{
+	snd_timer_user_t *tu;
+	int err;
+	
+	tu = file->private_data;
+	err = fasync_helper(fd, file, on, &tu->fasync);
+        if (err < 0)
+		return err;
+	return 0;
+}
+
+static ssize_t snd_timer_user_read(struct file *file, char __user *buffer, size_t count, loff_t *offset)
+{
+	snd_timer_user_t *tu;
+	long result = 0, unit;
+	int err = 0;
+	
+	tu = file->private_data;
+	unit = tu->tread ? sizeof(snd_timer_tread_t) : sizeof(snd_timer_read_t);
+	spin_lock_irq(&tu->qlock);
+	while ((long)count - result >= unit) {
+		while (!tu->qused) {
+			wait_queue_t wait;
+
+			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
+				err = -EAGAIN;
+				break;
+			}
+
+			set_current_state(TASK_INTERRUPTIBLE);
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&tu->qchange_sleep, &wait);
+
+			spin_unlock_irq(&tu->qlock);
+			schedule();
+			spin_lock_irq(&tu->qlock);
+
+			remove_wait_queue(&tu->qchange_sleep, &wait);
+
+			if (signal_pending(current)) {
+				err = -ERESTARTSYS;
+				break;
+			}
+		}
+
+		spin_unlock_irq(&tu->qlock);
+		if (err < 0)
+			goto _error;
+
+		if (tu->tread) {
+			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++], sizeof(snd_timer_tread_t))) {
+				err = -EFAULT;
+				goto _error;
+			}
+		} else {
+			if (copy_to_user(buffer, &tu->queue[tu->qhead++], sizeof(snd_timer_read_t))) {
+				err = -EFAULT;
+				goto _error;
+			}
+		}
+
+		tu->qhead %= tu->queue_size;
+
+		result += unit;
+		buffer += unit;
+
+		spin_lock_irq(&tu->qlock);
+		tu->qused--;
+	}
+	spin_unlock_irq(&tu->qlock);
+ _error:
+	return result > 0 ? result : err;
+}
+
+static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
+{
+        unsigned int mask;
+        snd_timer_user_t *tu;
+
+        tu = file->private_data;
+
+        poll_wait(file, &tu->qchange_sleep, wait);
+	
+	mask = 0;
+	if (tu->qused)
+		mask |= POLLIN | POLLRDNORM;
+
+	return mask;
+}
+
+#ifdef CONFIG_COMPAT
+#include "timer_compat.c"
+#else
+#define snd_timer_user_ioctl_compat	NULL
+#endif
+
+static struct file_operations snd_timer_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_timer_user_read,
+	.open =		snd_timer_user_open,
+	.release =	snd_timer_user_release,
+	.poll =		snd_timer_user_poll,
+	.unlocked_ioctl =	snd_timer_user_ioctl,
+	.compat_ioctl =	snd_timer_user_ioctl_compat,
+	.fasync = 	snd_timer_user_fasync,
+};
+
+static snd_minor_t snd_timer_reg =
+{
+	.comment =	"timer",
+	.f_ops =	&snd_timer_f_ops,
+};
+
+/*
+ *  ENTRY functions
+ */
+
+static snd_info_entry_t *snd_timer_proc_entry = NULL;
+
+static int __init alsa_timer_init(void)
+{
+	int err;
+	snd_info_entry_t *entry;
+
+#ifdef SNDRV_OSS_INFO_DEV_TIMERS
+	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1, "system timer");
+#endif
+	if ((entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL)) != NULL) {
+		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
+		entry->c.text.read = snd_timer_proc_read;
+		if (snd_info_register(entry) < 0) {
+			snd_info_free_entry(entry);
+			entry = NULL;
+		}
+	}
+	snd_timer_proc_entry = entry;
+	if ((err = snd_timer_register_system()) < 0)
+		snd_printk(KERN_ERR "unable to register system timer (%i)\n", err);
+	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER,
+					NULL, 0, &snd_timer_reg, "timer"))<0)
+		snd_printk(KERN_ERR "unable to register timer device (%i)\n", err);
+	return 0;
+}
+
+static void __exit alsa_timer_exit(void)
+{
+	struct list_head *p, *n;
+
+	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
+	/* unregister the system timer */
+	list_for_each_safe(p, n, &snd_timer_list) {
+		snd_timer_t *timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
+		snd_timer_unregister(timer);
+	}
+	if (snd_timer_proc_entry) {
+		snd_info_unregister(snd_timer_proc_entry);
+		snd_timer_proc_entry = NULL;
+	}
+#ifdef SNDRV_OSS_INFO_DEV_TIMERS
+	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
+#endif
+}
+
+module_init(alsa_timer_init)
+module_exit(alsa_timer_exit)
+
+EXPORT_SYMBOL(snd_timer_open);
+EXPORT_SYMBOL(snd_timer_close);
+EXPORT_SYMBOL(snd_timer_resolution);
+EXPORT_SYMBOL(snd_timer_start);
+EXPORT_SYMBOL(snd_timer_stop);
+EXPORT_SYMBOL(snd_timer_continue);
+EXPORT_SYMBOL(snd_timer_pause);
+EXPORT_SYMBOL(snd_timer_new);
+EXPORT_SYMBOL(snd_timer_notify);
+EXPORT_SYMBOL(snd_timer_global_new);
+EXPORT_SYMBOL(snd_timer_global_free);
+EXPORT_SYMBOL(snd_timer_global_register);
+EXPORT_SYMBOL(snd_timer_global_unregister);
+EXPORT_SYMBOL(snd_timer_interrupt);
+EXPORT_SYMBOL(snd_timer_system_resolution);