tonga mclk regression

Zhu, Rex Rex.Zhu at
Fri Oct 6 05:55:17 UTC 2017

Thanks Tom.

The attached patch can fix this bug.

Best Regards


From: StDenis, Tom
Sent: Thursday, October 5, 2017 9:42 PM
To: amd-gfx mailing list
Cc: Zhu, Rex; Deucher, Alexander
Subject: tonga mclk regression

I've bisected it to this commit

[root at fx6 linux2]# git bisect bad
df1e63942063a0638a5813e5904988d834db2665 is the first bad commit
commit df1e63942063a0638a5813e5904988d834db2665
Author: Rex Zhu <Rex.Zhu at>
Date:   Fri Sep 1 13:46:20 2017 +0800

     drm/amd/powerplay: delete eventmgr layer in poweprlay

     Reviewed-by: Alex Deucher <alexander.deucher at>
     Signed-off-by: Rex Zhu <Rex.Zhu at>
     Signed-off-by: Alex Deucher <alexander.deucher at>

:040000 040000 5b955ab18919974b351c81565044f3280253fe03
35f848a30a0b57d7fdee53133ae5d8e066406d8f M      drivers

The commit before this has a properly throttling mclk with
glmark2/xonotic-glx and this commit does not (locks at 300MHz).  Should
point that the commit ahead of this locks at 150MHz (lowest setting).

I haven't actually looked at this commit for a fix yet.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0002-drm-amd-powerplay-fix-mclk-can-t-switch-on-Tonga.patch
Type: text/x-patch
Size: 2257 bytes
Desc: 0002-drm-amd-powerplay-fix-mclk-can-t-switch-on-Tonga.patch
URL: <>

More information about the amd-gfx mailing list