Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932892AbbFJWMo (ORCPT ); Wed, 10 Jun 2015 18:12:44 -0400 Received: from mail-wi0-f196.google.com ([209.85.212.196]:35760 "EHLO mail-wi0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932488AbbFJWMj convert rfc822-to-8bit (ORCPT ); Wed, 10 Jun 2015 18:12:39 -0400 Date: Thu, 11 Jun 2015 01:12:36 +0300 From: Mihai =?UTF-8?B?RG9uyJt1?= To: Takashi Iwai Cc: Jonathan McDowell , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: Audio crackles with 4.1-rc1 Message-ID: <20150611011236.53bcd1fd@mdontu-l> In-Reply-To: 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> Organization: Home MIME-Version: 1.0 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: 1956 Lines: 52 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. -- Mihai Donțu -- 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/