From: Nathan Chancellor nathan@kernel.org
[ Upstream commit 41012d715d5d7b9751ae84b8fb255e404ac9c5d0 ]
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: Maíra 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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c index f47d82da115c..42a567e71439 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c @@ -6651,8 +6651,7 @@ static double CalculateUrgentLatency( return ret; }
- -static void UseMinimumDCFCLK( +static noinline_for_stack void UseMinimumDCFCLK( struct display_mode_lib *mode_lib, int MaxInterDCNTileRepeaters, int MaxPrefetchMode,