Re: [PATCH] drm/amd/display: Bump frame warning limit for clang builds of dml

On 8/21/26 17:32, [email protected] wrote:
> From: Ivan Lipski <[email protected]>
> 
> [Why&How]
> When building the DML files with clang without any sanitizer or LTO,
> the following -Wframe-larger-than errors break the build under
> CONFIG_WERROR:
> 
>    display_mode_vba_30.c: error: stack frame size (2512) exceeds limit
>      (2048) in 'dml30_ModeSupportAndSystemConfigurationFull'
>    display_mode_vba_31.c: error: stack frame size (2416) exceeds limit
>      (2048) in 'dml31_ModeSupportAndSystemConfigurationFull'
>    display_mode_vba_314.c: error: stack frame size (2392) exceeds limit
>      (2048) in 'dml314_ModeSupportAndSystemConfigurationFull'
> 
> Clang consistently spills more than gcc, pushing the frame past the 2048
> byte limit.
> 
> Apply an existing approach of increasing the warn stack size to the
> non-sanitizer path so plain clang builds use a 3072 byte limit.
> 
> Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5642
Reviewed-by: Mario Limonciello (AMD) <[email protected]>>
> Signed-off-by: Ivan Lipski <[email protected]>
> ---
>   drivers/gpu/drm/amd/display/dc/dml/Makefile | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> index 10d4ace04d4f1..99da9dbd62b75 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> @@ -36,7 +36,11 @@ ifneq ($(CONFIG_FRAME_WARN),0)
>               frame_warn_limit := 3072
>           endif
>       else
> -        frame_warn_limit := 2048
> +        ifeq ($(CONFIG_CC_IS_CLANG),y)
> +            frame_warn_limit := 3072
> +        else
> +            frame_warn_limit := 2048
> +        endif
>       endif
>   
>       ifeq ($(call test-lt, $(CONFIG_FRAME_WARN), $(frame_warn_limit)),y)