[PATCH] drm/msm/dpu: signedness bug in dpu_encoder_phys_cmd_tearcheck_config()

[Dmitry Baryshkov]

On Mon, 22 May 2023 at 11:47, Marijn Suijten
<marijn.suijten at somainline.org> wrote:
>
> On 2023-05-22 10:48:01, Dan Carpenter wrote:
> > The "vsync_hz" variable is used to store negative error codes so it
> > needs to be signed for the error checking to work correctly.
>
> Nicely spotted, but it it looks like we have more to fix then.  The type
> returned by dpu_kms_get_clk_rate() is u64:
>
> - Perhaps the int used in this patch is too small (though 19.2MHz vsync
>   clock ought to fit);
> - That function should also return a signed number as part of this
>   contract.

Please also include freedreno@ to the cc list when sending v2.

>
> - Marijn
>
> >
> > Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> > Signed-off-by: Dan Carpenter <dan.carpenter at linaro.org>
> > ---
> >  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > index 74470d068622..b29e6d1ba7f6 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > @@ -320,7 +320,7 @@ static void dpu_encoder_phys_cmd_tearcheck_config(
> >       struct dpu_hw_tear_check tc_cfg = { 0 };
> >       struct drm_display_mode *mode;
> >       bool tc_enable = true;
> > -     u32 vsync_hz;
> > +     int vsync_hz;
> >       struct dpu_kms *dpu_kms;
> >
> >       if (!phys_enc->hw_pp) {
> > --
> > 2.39.2
> >



-- 
With best wishes
Dmitry