FAILED: patch "[PATCH] drm/amd/powerplay/smu7: allow mclk switching with no displays" failed to apply to 4.16-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From a9b3c001650984993dc96e09e1c59f57b905fd2d Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 13 Feb 2018 14:26:54 -0500
Subject: [PATCH] drm/amd/powerplay/smu7: allow mclk switching with no displays

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@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
index 937971361b65..84600ff6f4de 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
@@ -2904,10 +2904,13 @@ static int smu7_apply_state_adjust_rules(struct pp_hwmgr *hwmgr,
 				    PHM_PlatformCaps_DisableMclkSwitchingForFrameLock);
 
 
-	disable_mclk_switching = ((1 < info.display_count) ||
-				  disable_mclk_switching_for_frame_lock ||
-				  smu7_vblank_too_short(hwmgr, mode_info.vblank_time_us) ||
-				  (mode_info.refresh_rate > 120));
+	if (info.display_count == 0)
+		disable_mclk_switching = false;
+	else
+		disable_mclk_switching = ((1 < info.display_count) ||
+					  disable_mclk_switching_for_frame_lock ||
+					  smu7_vblank_too_short(hwmgr, mode_info.vblank_time_us) ||
+					  (mode_info.refresh_rate > 120));
 
 	sclk = smu7_ps->performance_levels[0].engine_clock;
 	mclk = smu7_ps->performance_levels[0].memory_clock;