linux-kernel - Re: Audio crackles with 4.1-rc1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <s5hpp6ov1wv.wl-tiwai@suse.de>
Date:	Tue, 28 Apr 2015 15:05:20 +0200
From:	Takashi Iwai <tiwai@...e.de>
To:	Jonathan McDowell <noodles@...th.li>
Cc:	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: Audio crackles with 4.1-rc1

At Tue, 28 Apr 2015 13:35:18 +0100,
Jonathan McDowell wrote:
> 
> On Tue, Apr 28, 2015 at 02:00:17PM +0200, Takashi Iwai wrote:
> > At Tue, 28 Apr 2015 12:21:57 +0100,
> > Jonathan McDowell wrote:
> > > 
> > > Having upgraded to 4.1-rc1 from 4.0 I'm now hearing audio crackles at
> > > regular intervals. I'm fairly sure this is due to the HDA power save as
> > > once audio is playing things are fine, it's just when starting to play
> > > audio that I hear the crackle.
> > > 
> > > System is a Dell Latitude E7240. I haven't tried a bisect yet but will
> > > attempt to find some time to do so in the next few days. It looks like
> > > there have been some changes in sound/hda/ between 4.0 + 4.1-rc1 so I'll
> > > concentrate on those first.
> > > 
> > There are lots of code changes and enhancements wrt power saving in
> > 4.1, and bisection won't help so much, I'm afraid.
> > 
> > First off, check the device status while you hear crackles.
> > Is the codec in runtime suspend (aka power save)?  This can be seen in
> > /sys/bus/hdaudio/devices/*/power/runtime_status.  Then check the
> > runtime status of the controller, too, found in
> > /sys/class/sound/card?/device/power/runtime_status.
> 
> The cracking is definitely happening with the transition from suspended
> to active:
> 
> /sys/class/sound/card0/device/power/runtime_status:suspended
> /sys/class/sound/card1/device/power/runtime_status:active
> /sys/bus/hdaudio/devices/hdaudioC0D0/power/runtime_status:suspended
> /sys/bus/hdaudio/devices/hdaudioC1D0/power/runtime_status:active
> 
> card1 + C1D0 were suspended, I hit delete in a terminal to force a
> terminal bell, got the crackle and the state changed to active as above.

Ah, so it's a click noise that happens only once per runtime PM
transition?  I thought it were constant crackling noises from your
description ("regular intervals").

In anyway, please give alsa-info.sh output on both 4.0 and 4.1.


Takashi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/