ALSA: ctxfi - Replace atc lock to mutex

The spinlock in atc can cause a sleep in lock:

Kernel failure message 1:
BUG: sleeping function called from invalid context at mm/slub.c:1599
in_atomic(): 0, irqs_disabled(): 1, pid: 2537, name: gstreamer-prope
Pid: 2537, comm: gstreamer-prope Tainted: P
2.6.29.4-167.fc11.x86_64 #1
Call Trace:
  [<ffffffff8103ff0f>] __might_sleep+0x10b/0x110
  [<ffffffff810cd734>] __kmalloc+0x73/0x130
  [<ffffffffa0b4b142>] ? daio_rsc_init+0xaa/0x125 [snd_ctxfi]
  [<ffffffffa0b4b212>] dao_rsc_init+0x55/0x1c0 [snd_ctxfi]
  [<ffffffffa0b4b3d2>] dao_rsc_reinit+0x55/0x5d [snd_ctxfi]
  [<ffffffff813abd6c>] ? _spin_lock_irqsave+0x32/0x3b
  [<ffffffffa0b454fe>] atc_spdif_out_passthru+0x92/0x136 [snd_ctxfi]
  ...

Since the lock path is no critical path, it can be gracefully
replaced with a mutex.

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

2 files changed, 11 insertions, 15 deletions

diff --git a/sound/pci/ctxfi/ctatc.c b/sound/pci/ctxfi/ctatc.c
index 80fb2baed7a7..b0adc8094009 100644
--- a/sound/pci/ctxfi/ctatc.c
+++ b/sound/pci/ctxfi/ctatc.c
@@ -259,7 +259,6 @@ static int atc_pcm_playback_prepare(struct ct_atc *atc, struct ct_atc_pcm *apcm)
         int n_amixer = apcm->substream->runtime->channels, i = 0;
         int device = apcm->substream->pcm->device;
         unsigned int pitch;
-        unsigned long flags;
 
         if (NULL != apcm->src) {
                 /* Prepared pcm playback */
@@ -311,10 +310,10 @@ static int atc_pcm_playback_prepare(struct ct_atc *atc, struct ct_atc_pcm *apcm)
         src = apcm->src;
         for (i = 0; i < n_amixer; i++) {
                 amixer = apcm->amixers[i];
-                spin_lock_irqsave(&atc->atc_lock, flags);
+                mutex_lock(&atc->atc_mutex);
                 amixer->ops->setup(amixer, &src->rsc,
                                         INIT_VOL, atc->pcm[i+device*2]);
-                spin_unlock_irqrestore(&atc->atc_lock, flags);
+                mutex_unlock(&atc->atc_mutex);
                 src = src->ops->next_interleave(src);
                 if (NULL == src)
                         src = apcm->src;
@@ -865,7 +864,6 @@ static int
 spdif_passthru_playback_setup(struct ct_atc *atc, struct ct_atc_pcm *apcm)
 {
         struct dao *dao = container_of(atc->daios[SPDIFOO], struct dao, daio);
-        unsigned long flags;
         unsigned int rate = apcm->substream->runtime->rate;
         unsigned int status;
         int err;
@@ -885,7 +883,7 @@ spdif_passthru_playback_setup(struct ct_atc *atc, struct ct_atc_pcm *apcm)
                 return -ENOENT;
         }
 
-        spin_lock_irqsave(&atc->atc_lock, flags);
+        mutex_lock(&atc->atc_mutex);
         dao->ops->get_spos(dao, &status);
         if (((status >> 24) & IEC958_AES3_CON_FS) != iec958_con_fs) {
                 status &= ((~IEC958_AES3_CON_FS) << 24);
@@ -895,7 +893,7 @@ spdif_passthru_playback_setup(struct ct_atc *atc, struct ct_atc_pcm *apcm)
         }
         if ((rate != atc->pll_rate) && (32000 != rate))
                 err = atc_pll_init(atc, rate);
-        spin_unlock_irqrestore(&atc->atc_lock, flags);
+        mutex_unlock(&atc->atc_mutex);
 
         return err;
 }
@@ -908,7 +906,6 @@ spdif_passthru_playback_prepare(struct ct_atc *atc, struct ct_atc_pcm *apcm)
         struct dao *dao;
         int err;
         int i;
-        unsigned long flags;
 
         if (NULL != apcm->src)
                 return 0;
@@ -934,13 +931,13 @@ spdif_passthru_playback_prepare(struct ct_atc *atc, struct ct_atc_pcm *apcm)
                         src = apcm->src;
         }
         /* Connect to SPDIFOO */
-        spin_lock_irqsave(&atc->atc_lock, flags);
+        mutex_lock(&atc->atc_mutex);
         dao = container_of(atc->daios[SPDIFOO], struct dao, daio);
         amixer = apcm->amixers[0];
         dao->ops->set_left_input(dao, &amixer->rsc);
         amixer = apcm->amixers[1];
         dao->ops->set_right_input(dao, &amixer->rsc);
-        spin_unlock_irqrestore(&atc->atc_lock, flags);
+        mutex_unlock(&atc->atc_mutex);
 
         ct_timer_prepare(apcm->timer);
 
@@ -1088,7 +1085,6 @@ static int atc_spdif_out_set_status(struct ct_atc *atc, unsigned int status)
 
 static int atc_spdif_out_passthru(struct ct_atc *atc, unsigned char state)
 {
-        unsigned long flags;
         struct dao_desc da_dsc = {0};
         struct dao *dao;
         int err;
@@ -1096,7 +1092,7 @@ static int atc_spdif_out_passthru(struct ct_atc *atc, unsigned char state)
         struct rsc *rscs[2] = {NULL};
         unsigned int spos = 0;
 
-        spin_lock_irqsave(&atc->atc_lock, flags);
+        mutex_lock(&atc->atc_mutex);
         dao = container_of(atc->daios[SPDIFOO], struct dao, daio);
         da_dsc.msr = state ? 1 : atc->msr;
         da_dsc.passthru = state ? 1 : 0;
@@ -1114,7 +1110,7 @@ static int atc_spdif_out_passthru(struct ct_atc *atc, unsigned char state)
         }
         dao->ops->set_spos(dao, spos);
         dao->ops->commit_write(dao);
-        spin_unlock_irqrestore(&atc->atc_lock, flags);
+        mutex_unlock(&atc->atc_mutex);
 
         return err;
 }
@@ -1572,7 +1568,7 @@ int __devinit ct_atc_create(struct snd_card *card, struct pci_dev *pci,
         atc->msr = msr;
         atc->chip_type = chip_type;
 
-        spin_lock_init(&atc->atc_lock);
+        mutex_init(&atc->atc_mutex);
 
         /* Find card model */
         err = atc_identify_card(atc);
diff --git a/sound/pci/ctxfi/ctatc.h b/sound/pci/ctxfi/ctatc.h
index a03347232e84..9fe620ea5f3f 100644
--- a/sound/pci/ctxfi/ctatc.h
+++ b/sound/pci/ctxfi/ctatc.h
@@ -19,7 +19,7 @@
 #define CTATC_H
 
 #include <linux/types.h>
-#include <linux/spinlock_types.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/timer.h>
 #include <sound/core.h>
@@ -90,7 +90,7 @@ struct ct_atc {
         void (*unmap_audio_buffer)(struct ct_atc *atc, struct ct_atc_pcm *apcm);
         unsigned long (*get_ptp_phys)(struct ct_atc *atc, int index);
 
-        spinlock_t atc_lock;
+        struct mutex atc_mutex;
 
         int (*pcm_playback_prepare)(struct ct_atc *atc,
                                     struct ct_atc_pcm *apcm);