Bug#897993: random black flickering
On 2019-04-25 1:35 a.m., Eduard Bloch wrote:
> On Mon, 7 May 2018 12:15:37 +0200 =?UTF-8?Q?Michel_D=c3=a4nzer?= <michel@daenzer.net> wrote:
>> On 2018-05-05 04:20 PM, Eduard Bloch wrote:
>>> Package: xserver-xorg-video-amdgpu
>>> Version: 18.0.1-1
>>> Severity: normal
>>>
>>> Hello,
>>>
>>> my card (cheaper version of Rx560) has been working quite well for months.
>>> But I made a dist-upgrade a few weeks ago and since then I see strange
>>> flickering happening every few minutes, sometimes even multiple times
>>> per minute. Feels like a quick insertion of a black frame. Maybe a
>>> silent GPU reset or something?
>>>
>>> It seems to happen more often when mouse is moving and/or Firefox is
>>> active. First I suspected the application where I saw it most in the
>>> first days (another web browser) but now I see this happen from time to
>>> time with other applications, like the gvim window I see in front of me
>>> right now.
>>>
>>> First I attribute this to the amdgpu.dc=1 kernel option which I have set
>>> for testing purposes before, but removing it did not change the
>>> behavior.
>>
>> That's because DC is enabled by default for you, you need amdgpu.dc=0 to
>> disable it. This is a DC issue which is fixed in current 4.16.y upstream.
>
> Hi,
>
> not sure this was the issue or maybe the root cause is somewhere else.
> I got my graphics card replaced in the meantime (now a RX580) and the
> problem still appears, although less frequent. I can reproduce it well
> when screen config is set to 2560x1440 and 75Hz, latest Sid version of
> xserver-xorg-video-amdgpu.
Which kernel version? Have you tried disabling DC?
> And the temporarily visible overlay looks more like garbage (i.e. it
> feels like a quick GPU restart).
A GPU reset would take more time, and would likely leave your session
unusable without at least restarting Xorg.
> The flickering is much less disturbing if the moved window is a simple
> one, like xterm, so it might have some connection to the drawing
> performance?
It might be related to GPU load, e.g. to the GPU memory clock being
changed dynamically. You could try if forcing the clock to a certain
value avoids the problem.
--
Earthling Michel Dänzer | https://www.amd.com
Libre software enthusiast | Mesa and X developer
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