From: Jerry Zuo <Jerry.Zuo@amd.com>
Date: Thu, 5 Oct 2017 15:37:46 -0400
Subject: drm/amd/display: Fix a logic defect in cursor move
Git-commit: 886daac91d4c794fa76a0e5cf1101bdb329f3fe3
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Regression caused by: Ib98354194d7

Need to check crtc->stream before updating cursor attributes
and position.

Signed-off-by: Jerry Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3736,14 +3736,15 @@ static void handle_cursor_update(struct
 
 	attributes.pitch = attributes.width;
 
-	if (!dc_stream_set_cursor_attributes(crtc_state->stream,
-					     &attributes))
-		DRM_ERROR("DC failed to set cursor attributes\n");
+	if (crtc_state->stream) {
+		if (!dc_stream_set_cursor_attributes(crtc_state->stream,
+							 &attributes))
+			DRM_ERROR("DC failed to set cursor attributes\n");
 
-	if (crtc_state->stream)
 		if (!dc_stream_set_cursor_position(crtc_state->stream,
 						   &position))
 			DRM_ERROR("DC failed to set cursor position\n");
+	}
 }
 
 static void prepare_flip_isr(struct amdgpu_crtc *acrtc)