From: Shirish S <shirish.s@amd.com>
Date: Thu, 26 Oct 2017 11:47:42 +0530
Subject: drm/amd/display: fix null pointer dereference
Git-commit: 55d9038b0c680ec90e3a7d2440e717ac6a2a8064
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

While setting cursor position in case of mpo,
input_pixel_processor is not available for underlay,
hence add check of the same to avoid null pointer
access issue.

Signed-off-by: Shirish S <shirish.s@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_stream.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -288,7 +288,7 @@ bool dc_stream_set_cursor_position(
 			pos_cpy.enable = false;
 
 
-		if (ipp->funcs->ipp_cursor_set_position != NULL)
+		if (ipp !=NULL && ipp->funcs->ipp_cursor_set_position != NULL)
 			ipp->funcs->ipp_cursor_set_position(ipp, &pos_cpy, &param);
 
 		if (mi != NULL && mi->funcs->set_cursor_position != NULL)