On Thu, 11 Jun 2015 07:01:13 +0200 Takashi Iwai wrote: > At Thu, 11 Jun 2015 01:12:36 +0300, Mihai Donțu wrote: > > On Wed, 10 Jun 2015 20:23:01 +0200 Takashi Iwai wrote: > > > From: Takashi Iwai <ti...@suse.de> > > > Subject: [PATCH] ALSA: hda - Reduce click noise at power up > > > > > > Some machines suffer from click noises at power up with the recent > > > kernels, and this seems triggered at the power transition and the > > > immediate verb executions. As a workaround, put a short delay (10ms) > > > right after the D0 transition. > > > > > > There are a few places that have the same kind of delays, especially > > > in the resume path. I guess they can be removed (or reduced) after > > > this patch. But, since the delay is relatively small, let's do it > > > later as a cleanup. > > > > > > Reported-by: Mihai Donțu <mihai.do...@gmail.com> > > > Signed-off-by: Takashi Iwai <ti...@suse.de> > > > --- > > > sound/pci/hda/hda_codec.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c > > > index b7782212dd64..38f5509ee52f 100644 > > > --- a/sound/pci/hda/hda_codec.c > > > +++ b/sound/pci/hda/hda_codec.c > > > @@ -3077,6 +3077,9 @@ static unsigned int hda_set_power_state(struct > > > hda_codec *codec, > > > break; > > > } > > > > > > + if (power_state == AC_PWRST_D0) > > > + msleep(10); > > > + > > > return state; > > > } > > > > > > > I take back my previous observations. I was at work and did not have > > access to headphones (one of those days). Now I'm at home, it's 1 AM, > > very quiet, and I notice the following: > > > > * on speakers: the click reproduces but with _very_ low amplitude; > > msleep(100) is unnoticeable, but msleep(10) is, barely; > > * on headphones: the moment I plug them I hear a loud static sound > > (like an old, untuned AM radio). If I play something, the static > > disappears. If I pause, the static returns after ~15s. > > OK, then the patch is no-go. We need a bit deeper analysis. > > About the headphone problem: don't you get the same issue with 4.0.x? > Please take alsa-info.sh outputs on both 4.0.x and 4.1 before and > after plugging the headphone, and attach the outputs. > (Run the script with --no-upload option.)
No, 4.0.5 and all previous kernels (>= 3.12) are OK. I have attached a small tarball with the two files produced by alsa-info.sh. Thanks, -- Mihai Donțu
alsa-info.tar.gz
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