Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751202AbbFKFBU (ORCPT ); Thu, 11 Jun 2015 01:01:20 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53733 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790AbbFKFBP (ORCPT ); Thu, 11 Jun 2015 01:01:15 -0400 Date: Thu, 11 Jun 2015 07:01:13 +0200 Message-ID: From: Takashi Iwai To: Mihai =?UTF-8?B?RG9uyJt1?= Cc: Jonathan McDowell , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: Audio crackles with 4.1-rc1 In-Reply-To: <20150611011236.53bcd1fd@mdontu-l> References: <20150429112859.GY10148@earth.li> <20150430150131.GA10148@earth.li> <20150502150513.GF10148@earth.li> <20150519161911.GD28070@earth.li> <20150519215310.GF28070@earth.li> <20150610131755.0b906783@mdontu-l.dsd.bitdefender.biz> <20150610134135.327e2bdc@mdontu-l.dsd.bitdefender.biz> <20150610144551.4578ee99@mdontu-l.dsd.bitdefender.biz> <20150610192202.0e987fd0@mdontu-l.dsd.bitdefender.biz> <20150610194303.3b82609d@mdontu-l.dsd.bitdefender.biz> <20150611011236.53bcd1fd@mdontu-l> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.5 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2399 Lines: 64 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 > > 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 > > Signed-off-by: Takashi Iwai > > --- > > 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.) thanks, Takashi -- 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/