Bug 210983

Summary: [5.10.4 Regression] screen saver won't wake up on display connected to HDMI/DP port
Product: Platform Specific/Hardware Reporter: H.J. Lu (hjl.tools)
Component: x86-64Assignee: platform_x86_64 (platform_x86_64)
Status: RESOLVED CODE_FIX    
Severity: normal CC: grzegorz.alibozek, kai.vehmanen, leho, mark.blakeney, tclark77
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 5.10.4 Subsystem:
Regression: No Bisected commit-id:

Description H.J. Lu 2020-12-31 14:31:58 UTC 
Under 5.10.4 kernel on Intel NUC8i7BEH, after blank screen saver was enabled,
screen saver didn't wake up when keyboard was pressed.  I could still ssh into
the machine.  But display was blank.  Rebooting to 5.10.3 fixed the issue.
Comment 1 H.J. Lu 2020-12-31 17:23:11 UTC 
This is introduced by

commit db71bc7ef3edd98299f83c7dba80b2cdba32de23
Author: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Date:   Thu Dec 10 19:44:45 2020 +0200

    ALSA: hda/hdmi: fix silent stream for first playback to DP
    
    [ Upstream commit b1a5039759cb7bfcb2157f28604dbda0bca58598 ]
    
    A problem exists in enabling silent stream when connection type is
    DisplayPort. Silent stream programming is completed when a new DP
    receiver is connected, but infoframe transmission does not actually
    start until PCM is opened for the first time. This can result in audible
    gap of multiple seconds. This only affects the first PCM open.
    
    Fix the issue by properly assigning a converter to the silent stream,
    and modifying the required stream ID programming sequence.
    
    This change only affects Intel display audio codecs.
    
    BugLink: https://github.com/thesofproject/linux/issues/2468
    Fixes: 951894cf30f4 ("ALSA: hda/hdmi: Add Intel silent stream support")
    Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
    Link: https://lore.kernel.org/r/20201210174445.3134104-1-kai.vehmanen@linux.intel.com
    Signed-off-by: Takashi Iwai <tiwai@suse.de>
    Signed-off-by: Sasha Levin <sashal@kernel.org>

I have one display connected to HDMI port and another display connected to
USB C to HDMI converter.
Comment 2 Grzegorz Alibożek 2020-12-31 17:35:03 UTC 
I have similar problem on lenovo t480s with connected another display to DP via lenovo dock 40ag
Comment 3 H.J. Lu 2020-12-31 18:08:33 UTC 
Revert

commit db71bc7ef3edd98299f83c7dba80b2cdba32de23
Author: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Date:   Thu Dec 10 19:44:45 2020 +0200

    ALSA: hda/hdmi: fix silent stream for first playback to DP
    
fixed the problem for me.
Comment 4 Grzegorz Alibożek 2021-01-01 10:09:50 UTC 
I confirm, revert ALSA: hda/hdmi: fix silent stream for first playback to DP
solved problem for me.
Comment 5 Kai Vehmanen 2021-01-01 18:01:09 UTC 
Fix submitted to alsa-devel:
https://mailman.alsa-project.org/pipermail/alsa-devel/2021-January/178794.html

You can avoid the error with following module option:
options snd_hda_codec_hdmi enable_silent_stream=N
Comment 6 H.J. Lu 2021-01-01 20:37:50 UTC 
(In reply to Kai Vehmanen from comment #5)
> Fix submitted to alsa-devel:
> https://mailman.alsa-project.org/pipermail/alsa-devel/2021-January/178794.
> html

I verified that the patch fixed my problem.  Thanks.
Comment 7 Leho Kraav 2021-01-09 13:05:40 UTC 
I can confirm, with this patch, machine is now successfully able to resume from suspend when connected to USB Type-C monitor.
Comment 8 Kai Vehmanen 2021-01-11 14:36:23 UTC 
The fix was merged to 5.10.6 as:

adee1c5126ef "ALSA: hda/hdmi: Fix incorrect mutex unlock in silent_stream_disable()"

We should be ok to close the bug now.
Comment 9 H.J. Lu 2021-01-11 14:42:36 UTC 
Fixed in 5.10.6.