From: Alex Deucher Date: Thu, 11 May 2017 17:10:02 +0000 (-0400) Subject: drm/amdgpu/ci: disable mclk switching for high refresh rates (v2) X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~4^2~66 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1f6791d4f20831b41bb5553cec027beb290c5102;p=firefly-linux-kernel-4.4.55.git drm/amdgpu/ci: disable mclk switching for high refresh rates (v2) commit 0a646f331db0eb9efc8d3a95a44872036d441d58 upstream. Even if the vblank period would allow it, it still seems to be problematic on some cards. v2: fix logic inversion (Nils) bug: https://bugs.freedesktop.org/show_bug.cgi?id=96868 Acked-by: Christian König Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/amd/amdgpu/ci_dpm.c b/drivers/gpu/drm/amd/amdgpu/ci_dpm.c index 57a2e347f04d..0f0094b58d1f 100644 --- a/drivers/gpu/drm/amd/amdgpu/ci_dpm.c +++ b/drivers/gpu/drm/amd/amdgpu/ci_dpm.c @@ -893,6 +893,12 @@ static bool ci_dpm_vblank_too_short(struct amdgpu_device *adev) u32 vblank_time = amdgpu_dpm_get_vblank_time(adev); u32 switch_limit = adev->mc.vram_type == AMDGPU_VRAM_TYPE_GDDR5 ? 450 : 300; + /* disable mclk switching if the refresh is >120Hz, even if the + * blanking period would allow it + */ + if (amdgpu_dpm_get_vrefresh(adev) > 120) + return true; + if (vblank_time < switch_limit) return true; else