[PATCH 47/67] drm/amd/display: Check otg_master pointer before use it

[Zaeem Mohamed]

From: Rodrigo Siqueira <rodrigo.sique...@amd.com>

Coverity highlighted that the parameter otg_master is referenced before
the if condition that validates it, which means that the code might have
some attempt to access a null pointer. This commit addresses this issue
by moving the pointer verification to the beginning of the function and
initializing all the values right after it.

Acked-by: Zaeem Mohamed <zaeem.moha...@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.sique...@amd.com>
---
 .../gpu/drm/amd/display/dc/core/dc_resource.c | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c 
b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 7894d3e52a27..e047ea4ff3aa 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2077,15 +2077,23 @@ int resource_get_odm_slice_index(const struct pipe_ctx 
*pipe_ctx)
 int resource_get_odm_slice_dst_width(struct pipe_ctx *otg_master,
                bool is_last_segment)
 {
-       const struct dc_crtc_timing *timing = &otg_master->stream->timing;
-       int count = resource_get_odm_slice_count(otg_master);
-       int h_active = timing->h_addressable +
-                       timing->h_border_left +
-                       timing->h_border_right;
-       int width = h_active / count;
+       const struct dc_crtc_timing *timing;
+       int count;
+       int h_active;
+       int width;
        bool two_pixel_alignment_required = false;
 
-       if (otg_master && otg_master->stream_res.tg && otg_master->stream)
+       if (!otg_master || !otg_master->stream)
+               return 0;
+
+       timing = &otg_master->stream->timing;
+       count = resource_get_odm_slice_count(otg_master);
+       h_active = timing->h_addressable +
+                  timing->h_border_left +
+                  timing->h_border_right;
+       width = h_active / count;
+
+       if (otg_master->stream_res.tg && otg_master->stream)
                two_pixel_alignment_required = 
otg_master->stream_res.tg->funcs->is_two_pixels_per_container(timing);
 
        if ((width % 2) && two_pixel_alignment_required)
-- 
2.34.1