Heavy flickering on any multihead setup (RX 580)
My problem seems to be very similar to this 4 years old bug.
The problem has become heavier and heavier as the time has gone by.
The card is an AFOX RX580 4GB
.
It started with sporadic flickering when playing many videos
at once or playing a videogame a few months ago,
to now that I can't switch a webpage without all DP
monitors
going black for many seconds, (everything fine on HDMI
and DVI-D
).
While I've had 5 display connected I've managed to work around the bug setting
the DPM profile to low
, but with anything below 5 it strangely doesn't seem enough.
If I try to set anything higher than low
(i.e. as soon as the frequency raises from 300MHz)
displays flicker more to the point that setting the high
setting "permanently" turns off all
of them except the primary.
I've then enabled all GPU voltage/overclock options through the kernel commandline hoping that
lowering memory clock to the minimum (it goes and stay at maximum value, 1750 MHz, as soon
as I connect a second screen) could solve the problem, but I've read on this bug tracker that
is not possible to change the values in pp_dpm_mclk
when two displays are connected,
like with the old radeon
driver.
I've tested altering memory voltage values from 850 to 1100 mV with a 50mV threshold but
just switching to manual
profile from low
worse the flickering.
A thing I've noticed is flickering seems to be related more to cpu activity than gpu; for example it's heavier and heavier as soon as I start building something. In particular I'm reproducing the issue on a daily built live archlinux system and it's even worse when I load the system on ram instead than from disk.
I will provide relevant logs as soon as I double check them for personal info.
I can already say the only error in xorg.log
related to AMDGPU is
(EE) AMDGPU(0): drmmode_do_crtc_dpms cannot get last vblank counter
which at a first glance seems related to vga monitors EDID detection, so no clues.
Also I've checked it should not be an electrical problem since I've tried removing any other hardware from the pc and attaching the GPU to another PSU.
PS: I'm using cheap DP-to-VGA
chinese adapters but I don't think it's related because
- they worked well until last week;
- I tried them on a friend's GPU without any apparent issue.