[Bug 102646] [dc] Screen flickering under amdgpu-experimental [buggy auto power profile]

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=102646

--- Comment #23 from Ruben Harutyunyan <harutyunyan.ruben at gmail.com> ---
Hello!

I am having a similar (same?) issue on my RX580 (Asus STRIX TOC).
Seems to be an issue with MCLK switching.


Here is a video of it happening on the desktop:
https://www.youtube.com/edit?o=U&video_id=z28fFqNdjAY
(there is also screen flickering that's not seen on camera, but it doesn't
happen too often in contrary to the horizontal lines)

OBS is unable to campture the glitches though:
https://www.youtube.com/edit?o=U&video_id=iMEnprhBKFQ

Notes: 
1) Most of the time glitches happen when something new gets rendered. 
2) Google Chrome/Chromium always glitch (to a lesser extent when only the start
page is open and nothing changes on the screen, opening Facebook guarantees
glitches).
3) Playing video in VLC doesn't cause any glitches (x264 encoded MKV).
4) It's really easy to reproduce by setting the power profile to low (which
fixes the issue) and then switching to high while looking at the screen. The
glitch will occur for a split second. Switching from high to low also causes
the issue.

Workarounds so far:
1) Recompiling the kernel with "smu7_vblank_too_short" forced to output true
(aka disabling MCLK switching) fixes the problem but locks the MCLK at 2Ghz and
causes coil whine and higher temps.
2) Setting the power profile to anything but "auto".
3) Disabling DC.

It's also worth noting that in my case "low" power profile works fine, but R9
390x users seem to need "high" power profile to fix it (from the
"smu7_vblank_too_short" thread:
https://bugs.freedesktop.org/show_bug.cgi?id=96868#c32).

I can test any patches/programs/cases if you need it.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20180305/0327c73a/attachment.html>