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 18:33:01 +0000 (14:33 -0400)
commitb0f4b23fc3dbd8c5398e9ea9cf1f16a00d9006a2
treeed2b30002050f8ac4ed88b57dac773aad66ee666
parent1dbec5b4b0ef319d6961d3ecb7384b4f9ef9d358
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