From 5536c6d69376273d5210ce05b7d5d462f0dff9d6 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 8 May 2012 17:08:10 +0200 Subject: [PATCH] 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 --- sound/pci/hda/hda_codec.c | 23 +++++++++++++++++++++-- sound/pci/hda/hda_codec.h | 1 + 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 8bd34320ef91..30a3d8ff978b 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -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); diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h index 0fe64912cefc..77cd99531aae 100644 --- a/sound/pci/hda/hda_codec.h +++ b/sound/pci/hda/hda_codec.h @@ -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 */