drm/amd/display: Mark dml30's UseMinimumDCFCLK() as noinline for stack usage
authorNathan Chancellor <nathan@kernel.org>
Tue, 30 Aug 2022 20:34:09 +0000 (13:34 -0700)
committerAlex Deucher <alexander.deucher@amd.com>
Tue, 13 Sep 2022 18:27:00 +0000 (14:27 -0400)
commit41012d715d5d7b9751ae84b8fb255e404ac9c5d0
treee5459e8b4de9e0cdac23ad1c8b1f666b3afe9c3f
parent21485d3da659b66c37d99071623af83ee1c6733d
drm/amd/display: Mark dml30's UseMinimumDCFCLK() as noinline for stack usage

This function consumes a lot of stack space and it blows up the size of
dml30_ModeSupportAndSystemConfigurationFull() with clang:

  drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3542:6: error: stack frame size (2200) exceeds limit (2048) in 'dml30_ModeSupportAndSystemConfigurationFull' [-Werror,-Wframe-larger-than]
  void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib)
       ^
  1 error generated.

Commit a0f7e7f759cf ("drm/amd/display: fix i386 frame size warning")
aimed to address this for i386 but it did not help x86_64.

To reduce the amount of stack space that
dml30_ModeSupportAndSystemConfigurationFull() uses, mark
UseMinimumDCFCLK() as noinline, using the _for_stack variant for
documentation. While this will increase the total amount of stack usage
between the two functions (1632 and 1304 bytes respectively), it will
make sure both stay below the limit of 2048 bytes for these files. The
aforementioned change does help reduce UseMinimumDCFCLK()'s stack usage
so it should not be reverted in favor of this change.

Link: https://github.com/ClangBuiltLinux/linux/issues/1681
Reported-by: "Sudip Mukherjee (Codethink)" <sudipm.mukherjee@gmail.com>
Tested-by: MaĆ­ra Canal <mairacanal@riseup.net>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c