drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config()

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: 484e72d314 ("drm/stm: ltdc: add support of ycbcr pixel formats")
Link: https://github.com/ClangBuiltLinux/linux/issues/1575
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220222152045.484610-1-nathan@kernel.org
This commit is contained in:
Nathan Chancellor 2022-02-22 08:20:46 -07:00 committed by Philippe Cornu
parent a2151490cc
commit 3b2f68f196

View file

@ -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_ERROR("Unsupported pixel format: %u\n", drm_pix_fmt);
return;
}
/* Enable limited range */