[PATCH 3.16 108/136] ALSA: timer: Simplify error path in snd_timer_open()

3.16.80-rc1 review patch. If anyone has any objections, please let me know.

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From: Takashi Iwai tiwai@suse.de

commit 41672c0c24a62699d20aab53b98d843b16483053 upstream.

Just a minor refactoring to use the standard goto for error paths in snd_timer_open() instead of open code. The first mutex_lock() is moved to the beginning of the function to make the code clearer.

Signed-off-by: Takashi Iwai tiwai@suse.de [bwh: Backported to 3.16 as dependency of commit a39331867335 "ALSA: timer: Fix mutex deadlock at releasing card"] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- sound/core/timer.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-)

--- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -255,19 +255,20 @@ int snd_timer_open(struct snd_timer_inst struct snd_timer_instance *timeri = NULL; int err;

+ mutex_lock(&register_mutex); 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) { pr_debug("ALSA: timer: invalid slave class %i\n", tid->dev_sclass); - return -EINVAL; + err = -EINVAL; + goto unlock; } - mutex_lock(&register_mutex); timeri = snd_timer_instance_new(owner, NULL); if (!timeri) { - mutex_unlock(&register_mutex); - return -ENOMEM; + err = -ENOMEM; + goto unlock; } timeri->slave_class = tid->dev_sclass; timeri->slave_id = tid->device; @@ -278,13 +279,10 @@ int snd_timer_open(struct snd_timer_inst snd_timer_close_locked(timeri); timeri = NULL; } - mutex_unlock(&register_mutex); - *ti = timeri; - return err; + goto unlock; }

/* open a master instance */ - mutex_lock(&register_mutex); timer = snd_timer_find(tid); #ifdef CONFIG_MODULES if (!timer) { @@ -295,25 +293,26 @@ int snd_timer_open(struct snd_timer_inst } #endif if (!timer) { - mutex_unlock(&register_mutex); - return -ENODEV; + err = -ENODEV; + goto unlock; } if (!list_empty(&timer->open_list_head)) { timeri = list_entry(timer->open_list_head.next, struct snd_timer_instance, open_list); if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) { - mutex_unlock(&register_mutex); - return -EBUSY; + err = -EBUSY; + timeri = NULL; + goto unlock; } } if (timer->num_instances >= timer->max_instances) { - mutex_unlock(&register_mutex); - return -EBUSY; + err = -EBUSY; + goto unlock; } timeri = snd_timer_instance_new(owner, timer); if (!timeri) { - mutex_unlock(&register_mutex); - return -ENOMEM; + err = -ENOMEM; + goto unlock; } /* take a card refcount for safe disconnection */ if (timer->card) @@ -322,16 +321,16 @@ int snd_timer_open(struct snd_timer_inst timeri->slave_id = slave_id;

if (list_empty(&timer->open_list_head) && timer->hw.open) { - int err = timer->hw.open(timer); + err = timer->hw.open(timer); if (err) { kfree(timeri->owner); kfree(timeri); + timeri = NULL;

if (timer->card) put_device(&timer->card->card_dev); module_put(timer->module); - mutex_unlock(&register_mutex); - return err; + goto unlock; } }

@@ -342,6 +341,8 @@ int snd_timer_open(struct snd_timer_inst snd_timer_close_locked(timeri); timeri = NULL; } + + unlock: mutex_unlock(&register_mutex); *ti = timeri; return err;