https://bugs.freedesktop.org/show_bug.cgi?id=88658
Bug ID: 88658 Summary: Slow video playback on Kabini Product: Mesa Version: unspecified Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: Drivers/Gallium/radeonsi Assignee: dri-devel@lists.freedesktop.org Reporter: jtossenb@gmail.com QA Contact: dri-devel@lists.freedesktop.org
I am using a 64-bit Kabini based system (AMD Athlon 5350) with Kodi 14.0 on an up-to-date Arch linux. Kodi plays this https://dl-web.dropbox.com/get/hi10p_sample.mp4?w=AAC8qnXfS0xxWbd5Fc2bkvWxMx... small sample file fine with kernel 3.16.x, but with kernel >= 3.17 the playback is only 1 fps (like a slideshow). It is a hi10p video, so Kodi uses pure software decoding.
I've done a git bisect between 3.16 and 3.17-rc1 and found that 02376d8282b88f07d0716da6155094c8760b1a13 is the first bad commit.
commit 02376d8282b88f07d0716da6155094c8760b1a13 Author: Michel Dänzer michel.daenzer@amd.com Date: Thu Jul 17 19:01:08 2014 +0900
drm/radeon: Allow write-combined CPU mappings of BOs in GTT (v2)
v2: fix rebase onto drm-fixes
Signed-off-by: Michel Dänzer michel.daenzer@amd.com Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com
Then I applied the patch found in comment 30 of bug 84627 attachment 11024 (as I use 64-bit system).
This patch worked around the problem on 3.17 and on the latest 3.19-rc5 kernel as well and now Kodi plays the above video 24 fps.