[PATCH 4.15 027/146] drm/amd/powerplay/vega10: allow mclk switching with no displays

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Deucher <alexander.deucher@xxxxxxx>

commit 5825acf5c958a6820b04e9811caeb2f5e572bcd8 upstream.

If there are no displays attached, there is no reason to disable
mclk switching.

Fixes mclks getting set to high when there are no displays attached.

Reviewed-by: Eric Huang <JinhuiEric.Huang@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c
@@ -3208,10 +3208,13 @@ static int vega10_apply_state_adjust_rul
 	disable_mclk_switching_for_vr = PP_CAP(PHM_PlatformCaps_DisableMclkSwitchForVR);
 	force_mclk_high = PP_CAP(PHM_PlatformCaps_ForceMclkHigh);
 
-	disable_mclk_switching = (info.display_count > 1) ||
-				    disable_mclk_switching_for_frame_lock ||
-				    disable_mclk_switching_for_vr ||
-				    force_mclk_high;
+	if (info.display_count == 0)
+		disable_mclk_switching = false;
+	else
+		disable_mclk_switching = (info.display_count > 1) ||
+			disable_mclk_switching_for_frame_lock ||
+			disable_mclk_switching_for_vr ||
+			force_mclk_high;
 
 	sclk = vega10_ps->performance_levels[0].gfx_clock;
 	mclk = vega10_ps->performance_levels[0].mem_clock;