On Mon, Feb 7, 2022 at 8:53 AM Nathan Chancellor <nathan@xxxxxxxxxx> 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(-)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 5eeb32c9c9ce..447ddde1786c 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -624,7 +624,8 @@ static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fm
> break;
> default:
> /* RGB or not a YCbCr supported format */
> - break;
> + drm_err(plane->dev, "Unsupported pixel format: %u\n", drm_pix_fmt);
This is fine, but in the future you should add an explicit
#include <drm/drm_print.h>
to avoid implicit header dependencies (like the ones that Mingo is
trying to detangle) for the declaration of drm_err. `drm_vprintf`
needs it, too.
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> + return;
> }
>
> /* Enable limited range */
>
> base-commit: 542898c5aa5c6a3179dffb1d1606884a63f75fed
> --
> 2.35.1
>
--
Thanks,
~Nick Desaulniers
