drm/radeon: disable mclk switching with 120hz+ monitors
These tend to be problematic even if the vblank period is
long enough. This needs more investigation across a wider
range of displays. Disable for now.
bugs:
https://bugs.freedesktop.org/show_bug.cgi?id=87796
https://bugs.freedesktop.org/show_bug.cgi?id=89198
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 9f758d3..33cf410 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -852,6 +852,12 @@
single_display = false;
}
+ /* 120hz tends to be problematic even if they are under the
+ * vblank limit.
+ */
+ if (single_display && (r600_dpm_get_vrefresh(rdev) >= 120))
+ single_display = false;
+
/* certain older asics have a separare 3D performance state,
* so try that first if the user selected performance
*/