Bug 100281

Summary: CPU suspend & audio (alsa|pulseaudio) conflict
Product: Drivers Reporter: FJLOMACTEP (flomasters)
Component: Sound(ALSA)Assignee: Jaroslav Kysela (perex)
Status: NEW ---    
Severity: normal CC: aaron.lu, tiwai
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 3.19.0-21-generic Subsystem:
Regression: No Bisected commit-id:

Description FJLOMACTEP 2015-06-22 01:54:26 UTC 
When not touching mouse and keyboard audio stuttering appears. Stuttering appears when CPU load become slow down. In task manager i have seen normal cpu load approx 20-30 % and 3% when audio stuttering comes. When did not touch keyboard and mouse audio stuttering appears at 4 or 8 or 2 sec. and continues 4 - 5 sec. and this effect looping.

Sound cards recognized by the system:
00:07.0 Audio device [0403]: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High Definition Audio [10de:0774] (rev a1)
Sound cards recognized by ALSA:
00:07.0 Audio device [0403]: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High Definition Audio [10de:0774] (rev a1)
Sound cards recognized by ALSA, and activated:
00:07.0 Audio device [0403]: NVIDIA Corporation MCP72XE/MCP72P/MCP78U/MCP78S High Definition Audio [10de:0774] (rev a1)

00-00: ALC662 rev1 Analog : ALC662 rev1 Analog : playback 1 : capture 1
00-01: ALC662 rev1 Digital : ALC662 rev1 Digital : playback 1
00-02: ALC662 rev1 Alt Analog : ALC662 rev1 Alt Analog : capture 1
00-03: HDMI 0 : HDMI 0 : playback 1
   
alsactl version 1.0.29 or 1.0.28 - same effect.

3.19.0-21-generic #21-Ubuntu SMP Sun Jun 14 18:31:11 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux 

dmesg --level=err,warn: http://paste.debian.net/250409/
lspci                   http://paste.debian.net/250778/
lspci -v                http://paste.debian.net/250779/
Comment 1 FJLOMACTEP 2015-06-22 02:46:02 UTC 
Sorry, but same stuttering appears and in 3.19.0-15-generic, that i have not founded before updates. I don't know where from that bug comes.
Comment 2 FJLOMACTEP 2015-06-22 03:23:56 UTC 
Am not sure, but posible it is "xfce4 power manager" bug. Sorry for mistake.
Comment 3 FJLOMACTEP 2015-06-22 03:57:45 UTC 
It is not xfce power manager. I don't know what it is ;(
Comment 4 FJLOMACTEP 2015-06-22 05:33:16 UTC 
When go in suspend and back audio stuttering bug disappeared.
Comment 5 FJLOMACTEP 2015-06-22 15:19:46 UTC 
Audio stuttering appears only when CPU load very small. If there are some task taking busy CPU there are no problems.
Comment 6 Aaron Lu 2015-07-06 02:27:32 UTC 
Probably we should let the audio people take a look, move there.
Comment 7 Takashi Iwai 2015-07-06 15:20:44 UTC 
Are you using PulseAudio?  If yes, does the behavior happen without PA?  Or after changing the PA setup not to use tsched?