https://bugs.freedesktop.org/show_bug.cgi?id=93826
--- Comment #67 from Alex Deucher alexdeucher@gmail.com --- (In reply to iuno from comment #66)
(In reply to Alex Deucher from comment #65)
Yes, that is independent of the patch in attachment 131983 [details] [review] [review]. The driver disables dynamic mclk switching for refresh rates above 120 hz to avoid flickering.
Yes, I know it prevents flickering. Comment #62 was a reply and I mentioned this as *another* problem (high power draw), independent from the fixed one.
Do you get flickering at 144Hz without forcing the mclk to high? I.e., without these patches: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Do you know how this works on Windows? Do they increase voltage without raising clocks and could this be an option for amdgpu too?
It's not the mclk frequency or voltage, it's the blanking period for the display timing, it's apparently too short on some monitors at very high refresh rates for the mclk to finish switching in time. If part of the mclk switch happens outside of the vblank period, you end up with flickering or other display artifacts.