Bug 107929

Summary: High memory clock speed issue on R9 380
Product: DRI Reporter: sergej.schmidt91
Component: DRM/AMDgpuAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED MOVED QA Contact:
Severity: enhancement    
Priority: medium CC: harry.wentland, sunpeng.li
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
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Description sergej.schmidt91 2018-09-14 10:17:47 UTC 
Created attachment 141561 [details]
dmesg

My setup is Strix R9 380 and two monitors Samsung SyncMaster XL2370 und Asus VS278. I use Ubuntu 18.04 on 4.15 Kernel and Windows 10 in Dual Boot. If i use Ubuntu with two monitors, the memory clock raises to the maximum 1425mhz in Idle.

I already know that there is an issue with dual monitor setup on AMD GPUs but i tested it on Windows and there are no issues with these two monitors. When i have Chrome open and browse the internet it is mostly 300 or 700mhz. I just have to set both monitors to exactly 60 hertz.

1. On Linux i checked and set the monitors to 60 hertz.

2. I have tried the 4.18.7 and 4.19rc3 Kernel.

3. Installed the driver from AMD website.

4. I saw some commands for manual select of clock speed. ->Works only for GPU frequency.
echo manual > /sys/class/drm/card0/device/power_dpm_force_performance_level
echo 1 > /sys/class/drm/card0/device/pp_dpm_mclk

5. amdgpu.dc=1 amdgpu.dpm=1

None of these works.
Comment 1 Alex Deucher 2018-09-14 14:56:54 UTC 
We don't currently support mclk switching with multiple monitors in Linux.
Comment 2 Alex Deucher 2018-09-14 14:58:51 UTC 
On windows it's only supported if both monitors have the same timing and the vblank periods line up.  I'm not sure what's missing to enable this on Linux.  Harry?  Leo?
Comment 3 Martin Peres 2019-11-19 08:55:31 UTC 
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