Re: [PATCH] drm/msm/dpu: Fix variable dereferenced before check

[Dmitry Baryshkov]

On Tue, 21 Jun 2022 at 20:44, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> Copying freedreno

The patch needs to be sent to freedreno@. Otherwise it doesn't exist
in patchwork.

>
> On 6/21/2022 10:42 AM, Abhinav Kumar wrote:
> >
> >
> > On 6/21/2022 4:06 AM, sunliming wrote:
> >> Fixes the following smatch warning:
> >>
> >> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:261
> >> dpu_encoder_phys_wb_atomic_check() warn: variable dereferenced before
> >> check 'conn_state'
> >>
> >> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >> Signed-off-by: sunliming <sunliming@xxxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> >
> >> ---
> >>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 10 +++++-----
> >>   1 file changed, 5 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> >> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> >> index 59da348ff339..0ec809ab06e7 100644
> >> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> >> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
> >> @@ -252,11 +252,6 @@ static int dpu_encoder_phys_wb_atomic_check(
> >>       DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
> >>               phys_enc->wb_idx, mode->name, mode->hdisplay,
> >> mode->vdisplay);
> >> -    if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
> >> -        return 0;
> >> -
> >> -    fb = conn_state->writeback_job->fb;
> >> -
> >>       if (!conn_state || !conn_state->connector) {
> >>           DPU_ERROR("invalid connector state\n");
> >>           return -EINVAL;
> >> @@ -267,6 +262,11 @@ static int dpu_encoder_phys_wb_atomic_check(
> >>           return -EINVAL;
> >>       }
> >> +    if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
> >> +        return 0;
> >> +
> >> +    fb = conn_state->writeback_job->fb;
> >> +
> >>       DPU_DEBUG("[fb_id:%u][fb:%u,%u]\n", fb->base.id,
> >>               fb->width, fb->height);



-- 
With best wishes
Dmitry