[PATCH] drm/mgag200: Initialize delta variable in PLL compute function

[Daniel Vetter]

On Tue, Aug 17, 2021 at 8:16 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Initialize delta variable in PLL compute function for G200SE, rev 00 to
> the maximum value. Fixes uninitialized usage.
>
>   smatch warnings:
>   drivers/gpu/drm/mgag200/mgag200_pll.c:142 mgag200_pixpll_compute_g200se_00() \
>   error: uninitialized symbol 'delta'.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Fixes: 2545ac960364 ("drm/mgag200: Abstract pixel PLL via struct mgag200_pll")
> Reported-by: kernel test robot <lkp at intel.com>
> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: dri-devel at lists.freedesktop.org

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

I checked a bit your integer types, and there's a fair bit of
inconsistency for what you're using for clock. unsigned int, long, int
can all be found somewhere. But that's  different story.
-Daniel

> ---
>  drivers/gpu/drm/mgag200/mgag200_pll.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/mgag200/mgag200_pll.c b/drivers/gpu/drm/mgag200/mgag200_pll.c
> index 7c903cf19c0d..e9ae22b4f813 100644
> --- a/drivers/gpu/drm/mgag200/mgag200_pll.c
> +++ b/drivers/gpu/drm/mgag200/mgag200_pll.c
> @@ -124,6 +124,7 @@ static int mgag200_pixpll_compute_g200se_00(struct mgag200_pll *pixpll, long clo
>         unsigned int computed;
>
>         m = n = p = s = 0;
> +       delta = 0xffffffff;
>         permitteddelta = clock * 5 / 1000;
>
>         for (testp = 8; testp > 0; testp /= 2) {
> --
> 2.32.0
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch