ALSA: ctxfi - Fix Oops at mmapping

Replace a spinlock with a mutex protecting the vm block list at
mmap / munmap calls, which caused Oops like below:

BUG: sleeping function called from invalid context at mm/slub.c:1599
in_atomic(): 0, irqs_disabled(): 1, pid: 32065, name: xine
Pid: 32065, comm: xine Tainted: P           2.6.29.4-75.fc10.x86_64 #1
Call Trace:
  [<ffffffff81040685>] __might_sleep+0x105/0x10a
  [<ffffffff810c9fae>] kmem_cache_alloc+0x32/0xe2
  [<ffffffffa08e3110>] ct_vm_map+0xfa/0x19e [snd_ctxfi]
  [<ffffffffa08e1a07>] ct_map_audio_buffer+0x4c/0x76 [snd_ctxfi]
  [<ffffffffa08e2aa5>] atc_pcm_playback_prepare+0x1d7/0x2a8 [snd_ctxfi]
  [<ffffffff8105ef3f>] ? up_read+0x9/0xb
  [<ffffffff81186b61>] ? __up_read+0x7c/0x87
  [<ffffffffa08e36a6>] ct_pcm_playback_prepare+0x39/0x60 [snd_ctxfi]
  [<ffffffffa0886bcb>] snd_pcm_do_prepare+0x16/0x28 [snd_pcm]
  [<ffffffffa08867c7>] snd_pcm_action_single+0x2d/0x5b [snd_pcm]
  [<ffffffffa08881f3>] snd_pcm_action_nonatomic+0x52/0x6a [snd_pcm]
  [<ffffffffa088a723>] snd_pcm_common_ioctl1+0x404/0xc79 [snd_pcm]
  [<ffffffff810c52c8>] ? alloc_pages_current+0xb9/0xc2
  [<ffffffff810c9402>] ? new_slab+0x1a5/0x1cb
  [<ffffffff810ab9ea>] ? vma_prio_tree_insert+0x23/0xc1
  [<ffffffffa088b411>] snd_pcm_playback_ioctl1+0x213/0x230 [snd_pcm]
  [<ffffffff810b6c20>] ? mmap_region+0x397/0x4c9
  [<ffffffffa088bd9b>] snd_pcm_playback_ioctl+0x2e/0x36 [snd_pcm]
  [<ffffffff810ddc64>] vfs_ioctl+0x2a/0x78
  [<ffffffff810de130>] do_vfs_ioctl+0x462/0x4a2
  [<ffffffff81029cef>] ? default_spin_lock_flags+0x9/0xe
  [<ffffffff81374647>] ? trace_hardirqs_off_thunk+0x3a/0x6c
  [<ffffffff810de1c5>] sys_ioctl+0x55/0x77
  [<ffffffff8101133a>] system_call_fastpath+0x16/0x1b

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

1 files changed, 0 insertions, 11 deletions

diff --git a/sound/pci/ctxfi/ctatc.c b/sound/pci/ctxfi/ctatc.c
index ead104ea1e35..1a4bb357eaef 100644
--- a/sound/pci/ctxfi/ctatc.c
+++ b/sound/pci/ctxfi/ctatc.c
@@ -119,7 +119,6 @@ atc_pcm_release_resources(struct ct_atc *atc, struct ct_atc_pcm *apcm);
 
 static int ct_map_audio_buffer(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 {
-	unsigned long flags;
 	struct snd_pcm_runtime *runtime;
 	struct ct_vm *vm;
 
@@ -129,9 +128,7 @@ static int ct_map_audio_buffer(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 	runtime = apcm->substream->runtime;
 	vm = atc->vm;
 
-	spin_lock_irqsave(&atc->vm_lock, flags);
 	apcm->vm_block = vm->map(vm, runtime->dma_area, runtime->dma_bytes);
-	spin_unlock_irqrestore(&atc->vm_lock, flags);
 
 	if (NULL == apcm->vm_block)
 		return -ENOENT;
@@ -141,7 +138,6 @@ static int ct_map_audio_buffer(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 
 static void ct_unmap_audio_buffer(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 {
-	unsigned long flags;
 	struct ct_vm *vm;
 
 	if (NULL == apcm->vm_block)
@@ -149,9 +145,7 @@ static void ct_unmap_audio_buffer(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 
 	vm = atc->vm;
 
-	spin_lock_irqsave(&atc->vm_lock, flags);
 	vm->unmap(vm, apcm->vm_block);
-	spin_unlock_irqrestore(&atc->vm_lock, flags);
 
 	apcm->vm_block = NULL;
 }
@@ -161,9 +155,7 @@ static unsigned long atc_get_ptp_phys(struct ct_atc *atc, int index)
 	struct ct_vm *vm;
 	void *kvirt_addr;
 	unsigned long phys_addr;
-	unsigned long flags;
 
-	spin_lock_irqsave(&atc->vm_lock, flags);
 	vm = atc->vm;
 	kvirt_addr = vm->get_ptp_virt(vm, index);
 	if (kvirt_addr == NULL)
@@ -171,8 +163,6 @@ static unsigned long atc_get_ptp_phys(struct ct_atc *atc, int index)
 	else
 		phys_addr = virt_to_phys(kvirt_addr);
 
-	spin_unlock_irqrestore(&atc->vm_lock, flags);
-
 	return phys_addr;
 }
 
@@ -1562,7 +1552,6 @@ int ct_atc_create(struct snd_card *card, struct pci_dev *pci,
 	atc_set_ops(atc);
 
 	spin_lock_init(&atc->atc_lock);
-	spin_lock_init(&atc->vm_lock);
 
 	/* Find card model */
 	err = atc_identify_card(atc);