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ALSA: hda - Protect the power-saving count with spinlock 

To avoid some races.  Still not perfect, but now a bit safer.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2012-05-08 17:08:10 +02:00
parent 339876d70a
commit 5536c6d693
2 changed files with 22 additions and 2 deletions
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23
sound/pci/hda/hda_codec.c
View File

@ -1266,6 +1266,7 @@ int /*__devinit*/ snd_hda_codec_new(struct hda_bus *bus,
snd_array_init(&codec->spdif_out, sizeof(struct hda_spdif_out), 16);
#ifdef CONFIG_SND_HDA_POWER_SAVE
spin_lock_init(&codec->power_lock);
INIT_DELAYED_WORK(&codec->power_work, hda_power_work);
/* snd_hda_codec_new() marks the codec as power-up, and leave it as is.
* the caller has to power down appropriatley after initialization
@ -4292,12 +4293,16 @@ static void hda_power_work(struct work_struct *work)
container_of(work, struct hda_codec, power_work.work);
struct hda_bus *bus = codec->bus;
spin_lock(&codec->power_lock);
if (!codec->power_on || codec->power_count) {
codec->power_transition = 0;
spin_unlock(&codec->power_lock);
return;
}
trace_hda_power_down(codec);
spin_unlock(&codec->power_lock);
hda_call_codec_suspend(codec);
if (bus->ops.pm_notify)
bus->ops.pm_notify(bus);
@ -4305,9 +4310,11 @@ static void hda_power_work(struct work_struct *work)
static void hda_keep_power_on(struct hda_codec *codec)
{
spin_lock(&codec->power_lock);
codec->power_count++;
codec->power_on = 1;
codec->power_jiffies = jiffies;
spin_unlock(&codec->power_lock);
}
/* update the power on/off account with the current jiffies */
@ -4332,20 +4339,28 @@ void snd_hda_power_up(struct hda_codec *codec)
{
struct hda_bus *bus = codec->bus;
spin_lock(&codec->power_lock);
codec->power_count++;
if (codec->power_on || codec->power_transition)
if (codec->power_on || codec->power_transition) {
spin_unlock(&codec->power_lock);
return;
}
trace_hda_power_up(codec);
snd_hda_update_power_acct(codec);
codec->power_on = 1;
codec->power_jiffies = jiffies;
codec->power_transition = 1; /* avoid reentrance */
spin_unlock(&codec->power_lock);
if (bus->ops.pm_notify)
bus->ops.pm_notify(bus);
hda_call_codec_resume(codec);
spin_lock(&codec->power_lock);
cancel_delayed_work(&codec->power_work);
codec->power_transition = 0;
spin_unlock(&codec->power_lock);
}
EXPORT_SYMBOL_HDA(snd_hda_power_up);
@ -4361,14 +4376,18 @@ EXPORT_SYMBOL_HDA(snd_hda_power_up);
*/
void snd_hda_power_down(struct hda_codec *codec)
{
spin_lock(&codec->power_lock);
--codec->power_count;
if (!codec->power_on || codec->power_count || codec->power_transition)
if (!codec->power_on || codec->power_count || codec->power_transition) {
spin_unlock(&codec->power_lock);
return;
}
if (power_save(codec)) {
codec->power_transition = 1; /* avoid reentrance */
queue_delayed_work(codec->bus->workq, &codec->power_work,
msecs_to_jiffies(power_save(codec) * 1000));
}
spin_unlock(&codec->power_lock);
}
EXPORT_SYMBOL_HDA(snd_hda_power_down);

1
sound/pci/hda/hda_codec.h
View File

@ -867,6 +867,7 @@ struct hda_codec {
unsigned long power_on_acct;
unsigned long power_off_acct;
unsigned long power_jiffies;
spinlock_t power_lock;
#endif
/* codec-specific additional proc output */