Re: [PATCH 1/3] drm/msm/disp/dpu1: allow reservation even if dspps are not available.

[Dmitry Baryshkov]

On 17/01/2023 18:35, Dmitry Baryshkov wrote:
> On 17/01/2023 18:21, Kalyan Thota wrote:
> > if any topology requests for dspps and catalogue doesn't have the
> > allocation, avoid failing the reservation.
> >
> > This can pave way to build logic allowing composer fallbacks
> > for all the color features that are handled in dspp.
> >
> > Signed-off-by: Kalyan Thota <quic_kalyant@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 8 +++++++-
> >   1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c 
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> > index 73b3442..c8899ae 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> > @@ -343,7 +343,13 @@ static bool 
> > _dpu_rm_check_lm_and_get_connected_blks(struct dpu_rm *rm,
> >           return true;
> >       idx = lm_cfg->dspp - DSPP_0;
> > -    if (idx < 0 || idx >= ARRAY_SIZE(rm->dspp_blks)) {
> > +
> > +    if (idx < 0) {
>
> The change doesn't correspond to commit message.
>
> > +        DPU_DEBUG("lm doesn't have dspp, ignoring the request %d\n", 
> > lm_cfg->dspp);
> > +        return true;
> > +    }
> > +
> > +    if (idx >= ARRAY_SIZE(rm->dspp_blks)) {
> >           DPU_ERROR("failed to get dspp on lm %d\n", lm_cfg->dspp);
> >           return false;
> >       }
>
> If you'd like to remove duplicate for the (idx >= ARRAY_SIZE) check, I'd 
> suggest dropping the second one

I've misread the patch. However I don't see, why would one request 
DSPP_NONE while specifying topology->num_dspp. I think that you are 
trying to put additional logic into a function that should just check 
for the available resources.

--
With best wishes
Dmitry