drm/amd/display: Reduce number of arguments of dcn30's CalculatePrefetchSchedule()

Browse source

[ Upstream commit f54a91f533 ]

After an innocuous optimization change in clang-22,
dml30_ModeSupportAndSystemConfigurationFull() is over the 2048 byte
stack limit for display_mode_vba_30.c.

  drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3529:6: warning: stack frame size (2096) exceeds limit (2048) in 'dml30_ModeSupportAndSystemConfigurationFull' [-Wframe-larger-than]
   3529 | void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib)
        |      ^

With clang-21, this function was already close to the limit:

  drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3529:6: warning: stack frame size (1912) exceeds limit (1586) in 'dml30_ModeSupportAndSystemConfigurationFull' [-Wframe-larger-than]
   3529 | void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib)
        |      ^

CalculatePrefetchSchedule() has a large number of parameters, which must
be passed on the stack. Most of the parameters between the two callsites
are the same, so they can be accessed through the existing mode_lib
pointer, instead of being passed as explicit arguments. Doing this
reduces the stack size of dml30_ModeSupportAndSystemConfigurationFull()
from 2096 bytes to 1912 bytes with clang-22.

Closes: https://github.com/ClangBuiltLinux/linux/issues/2117
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit b20b3fc421)
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Nathan Chancellor 2025-12-13 19:58:10 +09:00 • committed by Greg Kroah-Hartman

parent eb5d6dedad

commit 6456713771

1 changed files with 73 additions and 185 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

258

drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c

View file