Re: 2.5.50: sleeping function called from illegal context

[Takashi Iwai <tiwai@suse.de>]

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At Tue, 3 Dec 2002 06:57:45 +0100,
Duncan Sands wrote:
> 
> On Tuesday 03 December 2002 14:56, Takashi Iwai wrote:
> > At Tue, 3 Dec 2002 04:55:15 +0100,
> >
> > Duncan Sands wrote:
> > > On Tuesday 03 December 2002 13:01, Takashi Iwai wrote:
> > > > At Tue, 3 Dec 2002 04:07:52 +0100,
> > > >
> > > > Duncan Sands wrote:
> > > > > Got this with today 2.5 BK tree:
> > > > >
> > > > > Debug: sleeping function called from illegal context at
> > > > > include/asm/semaphore.h:119 Call Trace:
> > > > >  [<c0113f1a>] __might_sleep+0x52/0x58
> > > > >  [<c024291a>] snd_cs46xx_iec958_put+0x36/0xf8
> > > > >  [<c0217f28>] snd_ctl_elem_write+0xe0/0x1a4
> > > > >  [<c0218360>] snd_ctl_ioctl+0x184/0x2c8
> > > > >  [<c01462e6>] sys_ioctl+0x1fa/0x244
> > > > >  [<c01088f7>] syscall_call+0x7/0xb
> > > >
> > > > ouch, we are using rwlock in the control ioctls.
> > > >
> > > > mutex is necessary for many controls, so we cannot suppress the use of
> > > > mutex in control callbacks.
> > > > but temporary unlocking looks ad-hoc, too...
> > >
> > > If I understand right, the problem is that snd_ctl_elem_write
> > > acquires control_rwlock, which is a rw spinlock.  It then calls
> > > snd_cs46xx_iec958_put which acquires chip->spos_mutex,
> > > which is a semaphore.  Thus the message.  Now I deduce
> > > from the fact that  you don't use read_lock_irqsave that the
> > > data structure is not read from interrupt context.  That means
> > > you are only protecting against other CPUs.  So why not use
> > > a semaphore instead of a spinlock?
> >
> > hmm, there are some places calling with irq lock.
> > for example, snd_ctl_notify() can be called from the interrupt handler
> > for some interrupts like h/w volume change.
> 
> Uh oh!
> 
> > however, it seems that a single rwlock is used for the management of
> > two different lists.  and snd_ctl_elem_write() uses card->controls
> > only, whereas snd_ctl_notify() uses card->ctl_files only.
> > hence, we can merge two locks, rwsem for card->controls and rwlock for
> > card->ctl_files.  i'll give a try.
> 
> I guess another way of dealing with this kind of problem is to use a
> semaphore rather than a spinlock, and a workqueue: when the interrupt
> comes in, the call to snd_ctl_notify is put on the queue, where it will later
> be run in process context, and can safely take the semaphore.

yes, basically what snd_ctl_notify() does is the same.
it queues an event and wakes up the sleepers.
thus, it's ok to separate the stuff from the semaphore.

the attached is a patch to rewrite the locks with rwsem.
please check whether it works for you.


thanks,

Takashi

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Index: alsa-kernel/include/core.h
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/include/core.h,v
retrieving revision 1.26
diff -u -r1.26 core.h
--- alsa-kernel/include/core.h	2 Dec 2002 09:25:18 -0000	1.26
+++ alsa-kernel/include/core.h	3 Dec 2002 14:29:58 -0000
@@ -24,6 +24,7 @@
 
 #include <linux/sched.h>		/* wake_up() */
 #include <asm/semaphore.h>		/* struct semaphore */
+#include <linux/rwsem.h>		/* struct rw_semaphore */
 
 /* Typedef's */
 typedef struct timeval snd_timestamp_t;
@@ -141,8 +142,8 @@
 	struct list_head devices;	/* devices */
 
 	unsigned int last_numid;	/* last used numeric ID */
-	rwlock_t control_rwlock;	/* control list lock */
-	rwlock_t control_owner_lock;	/* control list lock */
+	struct rw_semaphore controls_rwsem;	/* controls list lock */
+	rwlock_t ctl_files_rwlock;	/* ctl_files list lock */
 	int controls_count;		/* count of all controls */
 	struct list_head controls;	/* all controls for this card */
 	struct list_head ctl_files;	/* active control files */
Index: alsa-kernel/core/control.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/control.c,v
retrieving revision 1.17
diff -u -r1.17 control.c
--- alsa-kernel/core/control.c	2 Dec 2002 09:25:17 -0000	1.17
+++ alsa-kernel/core/control.c	3 Dec 2002 14:45:15 -0000
@@ -37,7 +37,7 @@
 
 #define snd_kctl_ioctl(n) list_entry(n, snd_kctl_ioctl_t, list)
 
-static rwlock_t snd_ioctl_rwlock = RW_LOCK_UNLOCKED;
+static DECLARE_RWSEM(snd_ioctl_rwsem);
 static LIST_HEAD(snd_control_ioctls);
 
 static inline void dec_mod_count(struct module *module)
@@ -82,9 +82,9 @@
 	ctl->card = card;
 	ctl->pid = current->pid;
 	file->private_data = ctl;
-	write_lock_irqsave(&card->control_rwlock, flags);
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
 	list_add_tail(&ctl->list, &card->ctl_files);
-	write_unlock_irqrestore(&card->control_rwlock, flags);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 	return 0;
 
       __error:
@@ -123,16 +123,16 @@
 	fasync_helper(-1, file, 0, &ctl->fasync);
 	file->private_data = NULL;
 	card = ctl->card;
-	write_lock_irqsave(&card->control_rwlock, flags);
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
 	list_del(&ctl->list);
-	write_lock(&card->control_owner_lock);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	down_write(&card->controls_rwsem);
 	list_for_each(list, &card->controls) {
 		control = snd_kcontrol(list);
 		if (control->owner == ctl)
 			control->owner = NULL;
 	}
-	write_unlock(&card->control_owner_lock);
-	write_unlock_irqrestore(&card->control_rwlock, flags);
+	up_write(&card->controls_rwsem);
 	snd_ctl_empty_read_queue(ctl);
 	snd_magic_kfree(ctl);
 	dec_mod_count(card->module);
@@ -151,7 +151,7 @@
 	snd_kctl_event_t *ev;
 	
 	snd_runtime_check(card != NULL && id != NULL, return);
-	read_lock_irqsave(&card->control_rwlock, flags);
+	read_lock(&card->ctl_files_rwlock);
 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 	card->mixer_oss_change_count++;
 #endif
@@ -160,7 +160,7 @@
 		ctl = snd_ctl_file(flist);
 		if (!ctl->subscribed)
 			continue;
-		spin_lock(&ctl->read_lock);
+		spin_lock_irqsave(&ctl->read_lock, flags);
 		list_for_each(elist, &ctl->events) {
 			ev = snd_kctl_event(elist);
 			if (ev->id.numid == id->numid) {
@@ -179,9 +179,9 @@
 	_found:
 		wake_up(&ctl->change_sleep);
 		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
-		spin_unlock(&ctl->read_lock);
+		spin_unlock_irqrestore(&ctl->read_lock, flags);
 	}
-	read_unlock_irqrestore(&card->control_rwlock, flags);
+	read_unlock(&card->ctl_files_rwlock);
 }
 
 snd_kcontrol_t *snd_ctl_new(snd_kcontrol_t * control)
@@ -233,11 +233,11 @@
 	snd_assert(kcontrol->info != NULL, return -EINVAL);
 	snd_assert(!(kcontrol->access & SNDRV_CTL_ELEM_ACCESS_READ) || kcontrol->get != NULL, return -EINVAL);
 	snd_assert(!(kcontrol->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kcontrol->put != NULL, return -EINVAL);
-	write_lock(&card->control_rwlock);
+	down_write(&card->controls_rwsem);
 	list_add_tail(&kcontrol->list, &card->controls);
 	card->controls_count++;
 	kcontrol->id.numid = ++card->last_numid;
-	write_unlock(&card->control_rwlock);
+	up_write(&card->controls_rwsem);
 	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &kcontrol->id);
 	return 0;
 }
@@ -245,10 +245,10 @@
 int snd_ctl_remove(snd_card_t * card, snd_kcontrol_t * kcontrol)
 {
 	snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
-	write_lock(&card->control_rwlock);
+	down_write(&card->controls_rwsem);
 	list_del(&kcontrol->list);
 	card->controls_count--;
-	write_unlock(&card->control_rwlock);
+	up_write(&card->controls_rwsem);
 	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &kcontrol->id);
 	snd_ctl_free_one(kcontrol);
 	return 0;
@@ -264,47 +264,46 @@
 	return snd_ctl_remove(card, kctl);
 }
 
+static snd_kcontrol_t *_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id); /* w/o lock */
+
 int snd_ctl_rename_id(snd_card_t * card, snd_ctl_elem_id_t *src_id, snd_ctl_elem_id_t *dst_id)
 {
 	snd_kcontrol_t *kctl;
 
-	kctl = snd_ctl_find_id(card, src_id);
-	if (kctl == NULL)
+	down_write(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, src_id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
 		return -ENOENT;
-	write_lock(&card->control_rwlock);
+	}
 	kctl->id = *dst_id;
 	kctl->id.numid = ++card->last_numid;
-	write_unlock(&card->control_rwlock);
+	up_write(&card->controls_rwsem);
 	return 0;
 }
 
-snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
+static snd_kcontrol_t *_ctl_find_numid(snd_card_t * card, unsigned int numid)
 {
 	struct list_head *list;
 	snd_kcontrol_t *kctl;
 
 	snd_runtime_check(card != NULL && numid != 0, return NULL);
-	read_lock(&card->control_rwlock);
 	list_for_each(list, &card->controls) {
 		kctl = snd_kcontrol(list);
-		if (kctl->id.numid == numid) {
-			read_unlock(&card->control_rwlock);
+		if (kctl->id.numid == numid)
 			return kctl;
-		}
 	}
-	read_unlock(&card->control_rwlock);
 	return NULL;
 }
 
-snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
+static snd_kcontrol_t *_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
 {
 	struct list_head *list;
 	snd_kcontrol_t *kctl;
 
 	snd_runtime_check(card != NULL && id != NULL, return NULL);
 	if (id->numid != 0)
-		return snd_ctl_find_numid(card, id->numid);
-	read_lock(&card->control_rwlock);
+		return _ctl_find_numid(card, id->numid);
 	list_for_each(list, &card->controls) {
 		kctl = snd_kcontrol(list);
 		if (kctl->id.iface != id->iface)
@@ -317,20 +316,38 @@
 			continue;
 		if (kctl->id.index != id->index)
 			continue;
-		read_unlock(&card->control_rwlock);
 		return kctl;
 	}
-	read_unlock(&card->control_rwlock);
 	return NULL;
 }
 
+/* exported: with read lock */
+snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
+{
+	snd_kcontrol_t *kctl;
+	down_read(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, id);
+	up_read(&card->controls_rwsem);
+	return kctl;
+}
+
+/* exported: with read lock */
+snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
+{
+	snd_kcontrol_t *kctl;
+	down_read(&card->controls_rwsem);
+	kctl = _ctl_find_numid(card, numid);
+	up_read(&card->controls_rwsem);
+	return kctl;
+}
+
 static int snd_ctl_card_info(snd_card_t * card, snd_ctl_file_t * ctl,
 			     unsigned int cmd, unsigned long arg)
 {
 	snd_ctl_card_info_t info;
 
 	memset(&info, 0, sizeof(info));
-	read_lock(&snd_ioctl_rwlock);
+	down_read(&snd_ioctl_rwsem);
 	info.card = card->number;
 	strncpy(info.id, card->id, sizeof(info.id) - 1);
 	strncpy(info.driver, card->driver, sizeof(info.driver) - 1);
@@ -338,7 +355,7 @@
 	strncpy(info.longname, card->longname, sizeof(info.longname) - 1);
 	strncpy(info.mixername, card->mixername, sizeof(info.mixername) - 1);
 	strncpy(info.components, card->components, sizeof(info.components) - 1);
-	read_unlock(&snd_ioctl_rwlock);
+	up_read(&snd_ioctl_rwsem);
 	if (copy_to_user((void *) arg, &info, sizeof(snd_ctl_card_info_t)))
 		return -EFAULT;
 	return 0;
@@ -364,7 +381,7 @@
 		dst = vmalloc(space * sizeof(snd_ctl_elem_id_t));
 		if (dst == NULL)
 			return -ENOMEM;
-		read_lock(&card->control_rwlock);
+		down_read(&card->controls_rwsem);
 		list.count = card->controls_count;
 		plist = card->controls.next;
 		while (offset-- > 0 && plist != &card->controls)
@@ -379,14 +396,14 @@
 			space--;
 			list.used++;
 		}
-		read_unlock(&card->control_rwlock);
+		up_read(&card->controls_rwsem);
 		if (list.used > 0 && copy_to_user(list.pids, dst, list.used * sizeof(snd_ctl_elem_id_t)))
 			return -EFAULT;
 		vfree(dst);
 	} else {
-		read_lock(&card->control_rwlock);
+		down_read(&card->controls_rwsem);
 		list.count = card->controls_count;
-		read_unlock(&card->control_rwlock);
+		up_read(&card->controls_rwsem);
 	}
 	if (copy_to_user(_list, &list, sizeof(list)))
 		return -EFAULT;
@@ -402,10 +419,10 @@
 	
 	if (copy_from_user(&info, _info, sizeof(info)))
 		return -EFAULT;
-	read_lock(&card->control_rwlock);
-	kctl = snd_ctl_find_id(card, &info.id);
+	down_read(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, &info.id);
 	if (kctl == NULL) {
-		read_unlock(&card->control_rwlock);
+		up_read(&card->controls_rwsem);
 		return -ENOENT;
 	}
 #ifdef CONFIG_SND_DEBUG
@@ -425,7 +442,7 @@
 			info.owner = -1;
 		}
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	if (result >= 0)
 		if (copy_to_user(_info, &info, sizeof(info)))
 			return -EFAULT;
@@ -443,8 +460,8 @@
 		return -ENOMEM;	
 	if (copy_from_user(control, _control, sizeof(*control)))
 		return -EFAULT;
-	read_lock(&card->control_rwlock);
-	kctl = snd_ctl_find_id(card, &control->id);
+	down_read(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, &control->id);
 	if (kctl == NULL) {
 		result = -ENOENT;
 	} else {
@@ -460,7 +477,7 @@
 				result = -EPERM;
 		}
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	if (result >= 0)
 		if (copy_to_user(_control, control, sizeof(*control)))
 			return -EFAULT;
@@ -480,8 +497,8 @@
 		return -ENOMEM;	
 	if (copy_from_user(control, _control, sizeof(*control)))
 		return -EFAULT;
-	read_lock(&card->control_rwlock);
-	kctl = snd_ctl_find_id(card, &control->id);
+	down_read(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, &control->id);
 	if (kctl == NULL) {
 		result = -ENOENT;
 	} else {
@@ -489,7 +506,6 @@
 		if (control->indirect != indirect) {
 			result = -EACCES;
 		} else {
-			read_lock(&card->control_owner_lock);
 			if (!(kctl->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 			    kctl->put == NULL ||
 			    (kctl->owner != NULL && kctl->owner != file)) {
@@ -499,16 +515,15 @@
 				if (result >= 0)
 					control->id = kctl->id;
 			}
-			read_unlock(&card->control_owner_lock);
 			if (result > 0) {
-				read_unlock(&card->control_rwlock);
+				up_read(&card->controls_rwsem);
 				snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
 				result = 0;
 				goto __unlocked;
 			}
 		}
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
       __unlocked:
 	if (result >= 0)
 		if (copy_to_user(_control, control, sizeof(*control)))
@@ -526,12 +541,11 @@
 	
 	if (copy_from_user(&id, _id, sizeof(id)))
 		return -EFAULT;
-	read_lock(&card->control_rwlock);
-	kctl = snd_ctl_find_id(card, &id);
+	down_write(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, &id);
 	if (kctl == NULL) {
 		result = -ENOENT;
 	} else {
-		write_lock(&card->control_owner_lock);
 		if (kctl->owner != NULL)
 			result = -EBUSY;
 		else {
@@ -539,9 +553,8 @@
 			kctl->owner_pid = current->pid;
 			result = 0;
 		}
-		write_unlock(&card->control_owner_lock);
 	}
-	read_unlock(&card->control_rwlock);
+	up_write(&card->controls_rwsem);
 	return result;
 }
 
@@ -554,12 +567,11 @@
 	
 	if (copy_from_user(&id, _id, sizeof(id)))
 		return -EFAULT;
-	read_lock(&card->control_rwlock);
-	kctl = snd_ctl_find_id(card, &id);
+	down_write(&card->controls_rwsem);
+	kctl = _ctl_find_id(card, &id);
 	if (kctl == NULL) {
 		result = -ENOENT;
 	} else {
-		write_lock(&card->control_owner_lock);
 		if (kctl->owner == NULL)
 			result = -EINVAL;
 		else if (kctl->owner != file)
@@ -569,9 +581,8 @@
 			kctl->owner_pid = 0;
 			result = 0;
 		}
-		write_unlock(&card->control_owner_lock);
 	}
-	read_unlock(&card->control_rwlock);
+	up_write(&card->controls_rwsem);
 	return result;
 }
 
@@ -646,16 +657,16 @@
 		return put_user(SNDRV_CTL_POWER_D0, (int *)arg) ? -EFAULT : 0;
 #endif
 	}
-	read_lock(&snd_ioctl_rwlock);
+	down_read(&snd_ioctl_rwsem);
 	list_for_each(list, &snd_control_ioctls) {
 		p = list_entry(list, snd_kctl_ioctl_t, list);
 		err = p->fioctl(card, ctl, cmd, arg);
 		if (err != -ENOIOCTLCMD) {
-			read_unlock(&snd_ioctl_rwlock);
+			up_read(&snd_ioctl_rwsem);
 			return err;
 		}
 	}
-	read_unlock(&snd_ioctl_rwlock);
+	up_read(&snd_ioctl_rwsem);
 	snd_printd("unknown ioctl = 0x%x\n", cmd);
 	return -ENOTTY;
 }
@@ -740,9 +751,9 @@
 	if (pn == NULL)
 		return -ENOMEM;
 	pn->fioctl = fcn;
-	write_lock(&snd_ioctl_rwlock);
+	down_write(&snd_ioctl_rwsem);
 	list_add_tail(&pn->list, &snd_control_ioctls);
-	write_unlock(&snd_ioctl_rwlock);
+	up_write(&snd_ioctl_rwsem);
 	return 0;
 }
 
@@ -752,17 +763,17 @@
 	snd_kctl_ioctl_t *p;
 
 	snd_runtime_check(fcn != NULL, return -EINVAL);
-	write_lock(&snd_ioctl_rwlock);
+	down_write(&snd_ioctl_rwsem);
 	list_for_each(list, &snd_control_ioctls) {
 		p = list_entry(list, snd_kctl_ioctl_t, list);
 		if (p->fioctl == fcn) {
 			list_del(&p->list);
-			write_unlock(&snd_ioctl_rwlock);
+			up_write(&snd_ioctl_rwsem);
 			kfree(p);
 			return 0;
 		}
 	}
-	write_unlock(&snd_ioctl_rwlock);
+	up_write(&snd_ioctl_rwsem);
 	snd_BUG();
 	return -EINVAL;
 }
@@ -821,13 +832,13 @@
 	struct list_head *flist;
 	snd_ctl_file_t *ctl;
 
-	read_lock_irq(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	list_for_each(flist, &card->ctl_files) {
 		ctl = snd_ctl_file(flist);
 		wake_up(&ctl->change_sleep);
 		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
 	}
-	read_unlock_irq(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	return 0;
 }
 
Index: alsa-kernel/core/init.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/init.c,v
retrieving revision 1.17
diff -u -r1.17 init.c
--- alsa-kernel/core/init.c	3 Dec 2002 11:02:36 -0000	1.17
+++ alsa-kernel/core/init.c	3 Dec 2002 14:30:16 -0000
@@ -99,8 +99,8 @@
 	card->number = idx;
 	card->module = module;
 	INIT_LIST_HEAD(&card->devices);
-	rwlock_init(&card->control_rwlock);
-	rwlock_init(&card->control_owner_lock);
+	init_rwsem(&card->controls_rwsem);
+	rwlock_init(&card->ctl_files_rwlock);
 	INIT_LIST_HEAD(&card->controls);
 	INIT_LIST_HEAD(&card->ctl_files);
 	spin_lock_init(&card->files_lock);
Index: alsa-kernel/core/pcm.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/pcm.c,v
retrieving revision 1.19
diff -u -r1.19 pcm.c
--- alsa-kernel/core/pcm.c	2 Dec 2002 09:25:17 -0000	1.19
+++ alsa-kernel/core/pcm.c	3 Dec 2002 14:28:54 -0000
@@ -698,7 +698,7 @@
 		return -ENODEV;
 
 	card = pcm->card;
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	list_for_each(list, &card->ctl_files) {
 		kctl = snd_ctl_file(list);
 		if (kctl->pid == current->pid) {
@@ -706,7 +706,7 @@
 			break;
 		}
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 
 	if (pstr->substream_count == 0)
 		return -ENODEV;
Index: alsa-kernel/core/rawmidi.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/rawmidi.c,v
retrieving revision 1.22
diff -u -r1.22 rawmidi.c
--- alsa-kernel/core/rawmidi.c	2 Dec 2002 09:25:18 -0000	1.22
+++ alsa-kernel/core/rawmidi.c	3 Dec 2002 14:31:09 -0000
@@ -412,7 +412,7 @@
 	add_wait_queue(&rmidi->open_wait, &wait);
 	while (1) {
 		subdevice = -1;
-		read_lock(&card->control_rwlock);
+		down_read(&card->controls_rwsem);
 		list_for_each(list, &card->ctl_files) {
 			kctl = snd_ctl_file(list);
 			if (kctl->pid == current->pid) {
@@ -420,7 +420,7 @@
 				break;
 			}
 		}
-		read_unlock(&card->control_rwlock);
+		up_read(&card->controls_rwsem);
 		err = snd_rawmidi_kernel_open(cardnum, device, subdevice, fflags, rawmidi_file);
 		if (err >= 0)
 			break;
Index: alsa-kernel/core/oss/mixer_oss.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/core/oss/mixer_oss.c,v
retrieving revision 1.14
diff -u -r1.14 mixer_oss.c
--- alsa-kernel/core/oss/mixer_oss.c	2 Dec 2002 09:25:18 -0000	1.14
+++ alsa-kernel/core/oss/mixer_oss.c	3 Dec 2002 14:36:03 -0000
@@ -562,7 +562,7 @@
 	struct slot *slot = (struct slot *)pslot->private_data;
 	
 	*left = *right = 100;
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
 		snd_mixer_oss_get_volume1_vol(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
 	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GVOLUME) {
@@ -579,7 +579,7 @@
 	} else if (slot->present & SNDRV_MIXER_OSS_PRESENT_GROUTE) {
 		snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	return 0;
 }
 
@@ -655,7 +655,7 @@
 	snd_card_t *card = fmixer->card;
 	struct slot *slot = (struct slot *)pslot->private_data;
 	
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	if (slot->present & SNDRV_MIXER_OSS_PRESENT_PVOLUME) {
 		snd_mixer_oss_put_volume1_vol(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_PVOLUME], left, right);
 		if (slot->present & SNDRV_MIXER_OSS_PRESENT_CVOLUME)
@@ -685,7 +685,7 @@
 			snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_GROUTE], left, right, 1);
 		}
 	}
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	return 0;
 }
 
@@ -698,9 +698,9 @@
 	int left, right;
 	
 	left = right = 1;
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_CSWITCH], &left, &right, 0);
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	*active = (left || right) ? 1 : 0;
 	return 0;
 }
@@ -714,9 +714,9 @@
 	int left, right;
 	
 	left = right = 1;
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	snd_mixer_oss_get_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_CROUTE], &left, &right, 1);
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	*active = (left || right) ? 1 : 0;
 	return 0;
 }
@@ -728,9 +728,9 @@
 	snd_card_t *card = fmixer->card;
 	struct slot *slot = (struct slot *)pslot->private_data;
 	
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_CSWITCH], active, active, 0);
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	return 0;
 }
 
@@ -741,9 +741,9 @@
 	snd_card_t *card = fmixer->card;
 	struct slot *slot = (struct slot *)pslot->private_data;
 	
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	snd_mixer_oss_put_volume1_sw(fmixer, pslot, slot->kcontrol[SNDRV_MIXER_OSS_ITEM_CROUTE], active, active, 1);
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	return 0;
 }
 
@@ -764,12 +764,11 @@
 		err = -ENOMEM;
 		goto __unlock;
 	}
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
 	snd_runtime_check(kctl != NULL, err = -ENOENT; goto __unlock);
 	snd_runtime_check(!(err = kctl->info(kctl, uinfo)), goto __unlock);
 	snd_runtime_check(!(err = kctl->get(kctl, uctl)), goto __unlock);
-	read_unlock(&card->control_rwlock);
 	for (idx = 0; idx < 32; idx++) {
 		if (!(mixer->mask_recsrc & (1 << idx)))
 			continue;
@@ -785,10 +784,8 @@
 		}
 	}
 	err = 0;
-	goto __unalloc;
       __unlock:
-      	read_unlock(&card->control_rwlock);
-      __unalloc:
+     	up_read(&card->controls_rwsem);
       	if (uctl)
       		kfree(uctl);
       	if (uinfo)
@@ -813,7 +810,7 @@
 		err = -ENOMEM;
 		goto __unlock;
 	}
-	read_lock(&card->control_rwlock);
+	down_read(&card->controls_rwsem);
 	kctl = snd_mixer_oss_test_id(mixer, "Capture Source", 0);
 	snd_runtime_check(kctl != NULL, err = -ENOENT; goto __unlock);
 	snd_runtime_check(!(err = kctl->info(kctl, uinfo)), goto __unlock);
@@ -838,7 +835,7 @@
 		snd_ctl_notify(fmixer->card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
 	err = 0;
       __unlock:
-	read_unlock(&card->control_rwlock);
+	up_read(&card->controls_rwsem);
 	if (uctl)
 		kfree(uctl);
 	if (uinfo)