Re: [PATCH] backlight: lp855x: fix unintialized function return

[Daniel Thompson]

On Fri, Aug 11, 2023 at 03:15:53PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> The function now returns an error code in some cases, but fails to initialize
> it in others:
>
> drivers/video/backlight/lp855x_bl.c:252:11: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>         else if (lp->mode == REGISTER_BASED)
>                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/video/backlight/lp855x_bl.c:256:9: note: uninitialized use occurs here
>         return ret;
>                ^~~
> drivers/video/backlight/lp855x_bl.c:252:7: note: remove the 'if' if its condition is always true
>         else if (lp->mode == REGISTER_BASED)
>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Since this case should not actually happen, return the -EINVAL code.
>
> Fixes: 5145531be5fba ("backlight: lp855x: Catch errors when changing brightness")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

I think we already received a patch for this:
https://lore.kernel.org/lkml/20230809163825.GA5056@xxxxxxxxx/T/


Daniel.