Takashi Iwai wrote:
At Tue, 08 May 2012 17:08:10 +0400, Konstantin Khlebnikov wrote:
This fixes regression in shd-hda-codec after 785f857d1cb0856b612b46a0545b74aa2 ("ALSA: hda - Set codec to D3 forcibly even if not used")
hda_set_power_state() call must be explicitly protected against recursive snd_hda_power_up/down() calls, otherwise it accidentally switches device into D0 right before suspend. As result after resume sound device stays in D3 state and does not works because driver believes that the device is on already.
Signed-off-by: Konstantin Khlebnikovkhlebnikov@openvz.org
Hrm, does this really fix your problem? The path is called only during the suspend. Then, in the resume path, the codec is all powered up anyway.
This fixes my problem: during suspend hda_set_power_state() calls snd_hda_power_up() it set codec->power_on = 1 and switches device into D0. At S3 resume codec->power_on == 1 but all devices actually in D3 state. As result on resume path device stays in D3, but after one power-save cycle all works again.
If the race between the leftover power-save work is really a culprit, the fix would be just calling cancel_delayed_work_sync() before that point...
Race was always there, my problem was caused by commit which mentioned above.
Whole this code is very racy, someone needs to fix it.
thanks,
Takashi
sound/pci/hda/hda_codec.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 7a8fcc4..a0ea9d6 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -5444,10 +5444,14 @@ int snd_hda_suspend(struct hda_bus *bus) list_for_each_entry(codec,&bus->codec_list, list) { if (hda_codec_is_power_on(codec)) hda_call_codec_suspend(codec);
else /* forcibly change the power to D3 even if not used */
else {/* forcibly change the power to D3 even if not used */codec->power_transition = 1; hda_set_power_state(codec, codec->afg ? codec->afg : codec->mfg, AC_PWRST_D3);codec->power_transition = 0;}-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/