Re: [PATCH] drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config()

From: Raphael Gallais-Pou
Date: Tue Feb 08 2022 - 04:01:27 EST


Hello Nathan,


On 2/7/22 17:53, Nathan Chancellor wrote:
> Clang warns:
>
> drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
> default:
> ^~~~~~~
> drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
> val |= LxPCR_YCEN;
> ^~~
> drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
> u32 val;
> ^
> = 0
> 1 warning generated.
>
> Use a return instead of break in the default case to fix the warning.
> Add an error message so that this return is not silent, which could hide
> issues in the future.
>
> Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1575
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> ---
> drivers/gpu/drm/stm/ltdc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)


Reviewed-by: Raphael Gallais-Pou <raphael.gallais-pou@xxxxxxxxxxx>


Thanks,

Raphaël