Bug 108613

Summary: amdgpu.dc=1 + xf86-video-amdgpu: changing to a GPU upscaling resolution resets pp_dpm_mclk
Product: DRI Reporter: tempel.julian
Component: DRM/AMDgpuAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED DUPLICATE QA Contact:
Severity: normal    
Priority: medium CC: harry.wentland, nicholas.kazlauskas
Version: DRI git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
dmesg.log
none
xorg.log none

Description tempel.julian 2018-10-31 19:57:05 UTC 
My display doesn't offer upscaling resolutions. However, amdgpu.dc=1 + xf86-video-amdgpu does.
When I change the resolution from native (2560x1440) to one of those automatically offered upscaling resolutions (e.g. 1920x1080), the value in "/sys/class/drm/card0/device/pp_dpm_mclk" gets set to default.

I changed it before like this (to prevent flickering with 75Hz with my display):

echo "manual" > /sys/class/drm/card0/device/power_dpm_force_performance_level
echo "2" >  /sys/class/drm/card0/device/pp_dpm_mclk

The VRAM runs with its maximum clock as long as I don't change resolution. When I change the resolution like described above, the VRAM clock again gets dynamically changed according to load, which introduces nasty flickering in my case.

The desired behavior would be that the change done to pp_dpm_mclk remains untouched when changing to a GPU upscaling resolution.

I haven't checked if pp_dpm_sclk is affected as well. Other powerplay/overdrive/fan settings remain untouched by resolution change.

Using latest linux-amd-staging-drm-next-wip-git kernel.
Xorg session
Comment 1 Michel Dänzer 2018-11-01 11:22:14 UTC 
Please attach the corresponding Xorg log file and output of dmesg.
Comment 2 tempel.julian 2018-11-01 12:19:57 UTC 
Created attachment 142327 [details]
dmesg.log
Comment 3 tempel.julian 2018-11-01 12:20:18 UTC 
Created attachment 142328 [details]
xorg.log
Comment 4 dwagner 2018-11-01 21:26:10 UTC 
This is most certainly a duplicate of bug https://bugs.freedesktop.org/show_bug.cgi?id=107141 (which I would really really like to be fixed one day...)
Comment 5 tempel.julian 2018-11-01 21:51:10 UTC 
Yeah, looks like that. It also happens when changing ttys.
Comment 6 Michel Dänzer 2018-11-02 14:06:13 UTC 

*** This bug has been marked as a duplicate of bug 107141 ***
Comment 7 bmilreu 2018-11-14 05:39:27 UTC 
I gave up trying to use my monitor at it's supported 75hz. Locking mclk to fix flickering works only temporarily because it resets at certain events (sleep/wake, resolution changes). Why is this resolved?

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