Date: Tue, 19 Dec 2017 16:36:10 -0800
From: vcaputo@pengaru.com
To: Pavel Machek <pavel@ucw.cz>
Cc: tglx@linutronix.de, linux-kernel <linux-kernel@vger.kernel.org>,
        Takashi Iwai <tiwai@suse.de>
Subject: Re: thinkpad x60: sound problems in 4.15-rc1 was Re: thinkpad x60:
 sound problems in 4.14.0-next-20171114
Message-ID: <20171220003610.vogk3wrke47drsfw@shells.gnugeneration.com>
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 <20171127184411.GA22165@amd>
 <s5hindulwfv.wl-tiwai@suse.de>
 <20171214095730.GA6150@amd>
 <20171219020658.qpvxx7fqvrisezs6@shells.gnugeneration.com>
 <20171219045415.46croaosad656d5v@shells.gnugeneration.com>
 <20171219231256.dpizizz55o27op3s@shells.gnugeneration.com>
 <20171219232212.GA5177@amd>
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On Wed, Dec 20, 2017 at 12:22:12AM +0100, Pavel Machek wrote:
> Hi!
> 
> > > > > > > > > > > Reappeared, 4.15-rc1.
> > > > > > > > > > > 
> > > > > > > > > > > [   40.473822] PM: suspend exit
> > > > > > > > > > > [   40.526027] sdhci-pci 0000:15:00.2: Will use DMA mode even though
> > > > > > > > > > > HW doesn't fully claim to support it.
> > > > > > > > > > > [   40.569765] e1000e: eth1 NIC Link is Down
> > > > > > > > > > > [   40.578257] sdhci-pci 0000:15:00.2: Will use DMA mode even though
> > > > > > > > > > > HW doesn't fully claim to support it.
> > > > > > > > > > > [   40.648476] sdhci-pci 0000:15:00.2: Will use DMA mode even though
> > > > > > > > > > > HW doesn't fully claim to support it.
> > > > > > > > > > > [   40.737339] sdhci-pci 0000:15:00.2: Will use DMA mode even though
> > > > > > > > > > > HW doesn't fully claim to support it.
> > > > > > > > > > > [   43.018955] wlan0: authenticate with 00:00:00:00:00:01
> > > > > > > > > > > [   43.019072] wlan0: send auth to 00:00:00:00:00:01 (try 1/3)
> > > > > > > > > > > [   43.023955] wlan0: authenticated
> > > > > > > > > > > [   43.031721] wlan0: associate with 00:00:00:00:00:01 (try 1/3)
> > > > > > > > > > > [   43.039733] wlan0: RX AssocResp from 00:00:00:00:00:01 (capab=0x401
> > > > > > > > > > > status=0 aid=1)
> > > > > > > > > > > [   43.042712] wlan0: associated
> > > > > > > > > > > [  480.662456] snd_hda_intel 0000:00:1b.0: IRQ timing workaround is
> > > > > > > > > > > activated for card #0. Suggest a bigger bdl_pos_adj.
> > > > > > > > > > 
> > > > > > > > > > This message is often superfluous, so don't take this too seriously.
> > > > > > > > > > 
> > > > > > > > > > 
> > > > > > > > > > > pavel@amd:~$
> > > > > > > > > > > 
> > > > > > > > > > > Again, mplayer has problems, mpg123 works. This time mplayer started
> > > > > > > > > > > playing video (w/o sound) after long delay.
> > > > > > > > > > > 
> > > > > > > > > > > Uh. huh. And now problems appeared in mpg123, too, and then went away
> > > > > > > > > > > in mpg123 _and_ mplayer. Interesting.
> > > > > > > > > > > 
> > > > > > > > > > > I suspect some pulseaudio fun. chromium always has sound problems,
> > > > > > > > > > > then I restart chromium and everything is ok. But something changed in
> > > > > > > > > > > -next and 4.15-rc1, because mplayer did not have problems before.
> > > > > > > > > > 
> > > > > > > > > > Hm, there is no code change at all in sound/*.  If it happens only in
> > > > > > > > > > linux-next, it must be something else...
> > > > > > > > > 
> > > > > > > > > It happened first in -next, now it is in 4.15-rc1.
> > > > > > > > 
> > > > > > > > So you meant a possible regression between 4.14 and 4.15-rc1?
> > > > > > > 
> > > > > > > Yes.
> > > > > > 
> > > > > > Hm, as far as I see, the only significant difference is the commit
> > > > > > 20e3f985bb875fea4f86b04eba4b6cc29bfd6b71
> > > > > >     ALSA: pcm: update tstamp only if audio_tstamp changed
> > > > > >     
> > > > > > Another change d6c0615f510bc1ee26cfb2b9a3343ac99b9c46fb
> > > > > >     ALSA: hda - Fix yet remaining issue with vmaster 0dB
> > > > > >     initialization
> > > > > > is basically for fixing a previous wrong fix, and it should influence
> > > > > > on all use cases, not only for a specific application.
> > > > > 
> > > > > Happened again, this time on -rc3. It is more than "audio is silent"
> > > > > -- apps behave strangely. Let me test with
> > > > > 20e3f985bb875fea4f86b04eba4b6cc29bfd6b71 reverted.
> > > > > 
> > > > > Hmm. This is 4th regression this release cycle :-(.
> > > > 
> > > > 
> > > > Today I jumped to 4.15-rc4 from 4.14-rc6, and have noticed some oddities
> > > > with audio in youtube under firefox which I never experienced before.
> > > > 
> > > > If I pause the playback, the audio seems to infinitely loop on whatever
> > > > is in the dma buffer.  Resuming playback works but now the expected
> > > > audio has repeated pops and clicks mixed in with it.
> > > > 
> > > > Even closing firefox doesn't seem to stop the looping buffer...
> > > > 
> > > > Machine is an x61s 1.8ghz thinkpad, x86_64, debian stretch, .config attached.
> > > > 
> > > > This for me is a 4.15 blocker, and I presume it's related to Pavel's
> > > > experience as the x60 isn't much different AFAIK.
> > > > 
> > > 
> > > Just reproduced this, it seems to be trivial to repro and doesn't
> > > actually require pausing or anything.  Simply watching a youtube video
> > > causes the audio to get messed up after a short period.
> > > 
> > > I monitored `journalctl --dmesg --follow` while reproducing this and saw
> > > this line appear at the very moment the audio got messed up:
> > > 
> > >   kernel: Monitor-Mwait will be used to enter C-3 state
> > > 
> > > Prior to that, everything seemed to be owrking fine.
> > > 
> > 
> > After a lengthy bisect, I ended up with this being the bad commit:
> 
> You forgot to mention commit id :-).
> 

That is very strange, anyhow:

 commit fdba46ffb4c203b6e6794163493fd310f98bb4be
 Author: Thomas Gleixner <tglx@linutronix.de>
 Date:   Wed Sep 13 23:29:27 2017 +0200

     x86/apic: Get rid of multi CPU affinity


Will try reverting soon, just a bit busy today out in the desert and the sun
is going down so my solar panel is useless.

Regards,
Vito Caputo