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 <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/ci_dpm.c b/drivers/gpu/drm/amd/amdgpu/ci_dpm.c
index 57a2e347f04dc33a0f34394895900bf2d0552aa5..0f0094b58d1fe14cfead7d936b545d2b741b32d7 100644 (file)
--- 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