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scurrvy2020

Member

Registered: 2019-09-10

Posts: 8

VAAPI lags with 5.12.x kernel, resolves with 5.11.16 on baytrail, i965

Hi, I'm posting this here because I've more or less determined this to be an issue with the kernel.  I only noticed the issue recently, as I do not use this laptop often.

After about 3 minutes of h.264 hardware accelerated video, it will start to lag.  I rolled back to earlier versions of libva, libva-intel-driver, mesa, etc. Upgraded to mesa-git.  The problem persisted.

I switched to the linux-lts kernel and the video started playing in slow motion, about half speed.

I downgraded to linux-5.11.16 and the video plays at the correct speed and without lags for about one hour now.

There are no error messages in dmesg or journalctl when the video starts to lag.  It appears to be a kernel regression between 5.11 and 5.12. 

I'm afraid that is as far as I can diagnose this issue.

Edit: I tried to replicate the issue with my Haswell laptop that also uses i965 for vaapi. I did not have any issues with 5.12.x and haswell.

Last edited by scurrvy2020 (2021-05-22 04:44:58)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,230

Re: VAAPI lags with 5.12.x kernel, resolves with 5.11.16 on baytrail, i965

Which 5.12.x kernels did you test? Everything before .4-arch2 had the new kfence interface enabled that lead to quite a few performance regressions.

scurrvy2020

Member

Registered: 2019-09-10

Posts: 8

Re: VAAPI lags with 5.12.x kernel, resolves with 5.11.16 on baytrail, i965

I tried 5.12.3-arch2 and 5.12.6-arch1 and both had problems playing vaapi accelerated video.

I sorted out my audio pitch problem (pulseaudio sampling rate issue) and am now running that without an issue.