mainline build failure due to 5d8c3e836fc2 ("drm/amd/display: fix array-bounds error in dc_stream_remove_writeback()")

[Sudip Mukherjee (Codethink)]

Hi All,

The latest mainline kernel branch fails to build allmodconfig for every
ARCH with gcc-11 with the error:

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c: In function 'dc_stream_remove_writeback':
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:527:83: error: array subscript [0, 0] is outside array bounds of 'struct dc_writeback_info[1]' [-Werror=array-bounds]
  527 |                                 stream->writeback_info[j] = stream->writeback_info[i];
      |                                                             ~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from ./drivers/gpu/drm/amd/amdgpu/../display/dc/dc.h:1269,
                 from ./drivers/gpu/drm/amd/amdgpu/../display/dc/inc/core_types.h:29,
                 from ./drivers/gpu/drm/amd/amdgpu/../display/dc/basics/dc_common.h:29,
                 from drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:27:
./drivers/gpu/drm/amd/amdgpu/../display/dc/dc_stream.h:241:34: note: while referencing 'writeback_info'
  241 |         struct dc_writeback_info writeback_info[MAX_DWB_PIPES];
      |                                  ^~~~~~~~~~~~~~


git bisect pointed to 5d8c3e836fc2 ("drm/amd/display: fix array-bounds error in dc_stream_remove_writeback()")

I will be happy to test any patch or provide any extra log if needed.

Note:
This is only seen with gcc-11, gcc-12 builds are ok.


-- 
Regards
Sudip