drm/amd/display: Only allow VRR when vrefresh is within supported range

Nicholas Kazlauskas · alexdeucher · commit 0ab925d36906 · 2019-03-21T14:34:59.000-05:00
[Why]
Black screens or artifacting can occur when enabling FreeSync outside
of the supported range of the monitor. This can happen since the
supported range isn't always the min/max vrefresh range available for
the monitor.

[How]
There was previously a fix that prevented this from happening in the
low range but it didn't cover the upper range. Expand the condition
to include both.

Cc: Sun peng Li &lt;Sunpeng.Li@amd.com&gt;
Cc: Harry Wentland &lt;Harry.Wentland@amd.com&gt;
Signed-off-by: Nicholas Kazlauskas &lt;nicholas.kazlauskas@amd.com&gt;
Acked-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Reviewed-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5429,9 +5429,11 @@ static void get_freesync_config_for_crtc(
 	struct amdgpu_dm_connector *aconnector =
 			to_amdgpu_dm_connector(new_con_state->base.connector);
 	struct drm_display_mode *mode = &new_crtc_state->base.mode;
+	int vrefresh = drm_mode_vrefresh(mode);
 
 	new_crtc_state->vrr_supported = new_con_state->freesync_capable &&
-		aconnector->min_vfreq <= drm_mode_vrefresh(mode);
+					vrefresh >= aconnector->min_vfreq &&
+					vrefresh <= aconnector->max_vfreq;
 
 	if (new_crtc_state->vrr_supported) {
 		new_crtc_state->stream->ignore_msa_timing_param = true;
