On Thu, Jan 09, 2025 at 12:40:23PM +0800, Jun Nie wrote:
> Jessica Zhang <quic_jesszhan@quicinc.com> 于2025年1月9日周四 09:29写道：
> >
> >
> >
> > On 12/18/2024 11:49 PM, Jun Nie wrote:
> > > Add the case to reserve multiple pairs mixers for high resolution.
> > > Current code only supports one pair of mixer usage case. To support
> > > quad-pipe usage case, two pairs of mixers are needed.
> > >
> > > Current code resets number of mixer on failure of pair's peer test and
> > > retry on another pair. If two pairs are needed, the failure on the test
> > > of 2nd pair results clearing to the 1st pair. This patch only clear the
> > > bit for the 2nd pair allocation before retry on another pair.
> >
> > Hi Jun,
> >
> > I think the commit message wording is a bit unclear. Maybe something
> > like "Reset the current lm_count to an even number instead of completely
> > clearing it. This prevents all pairs from being cleared in cases where
> > multiple LM pairs are needed"
>
> Thanks for the suggestion! Will adopt it.
> >
> > >
> > > Signed-off-by: Jun Nie <jun.nie@linaro.org>
> > > ---
> > > drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 6 +++++-
> > > 1 file changed, 5 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 cde3c5616f9bc..a8b01b78c02c7 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> > > @@ -316,7 +316,11 @@ static int _dpu_rm_reserve_lms(struct dpu_rm *rm,
> > > if (!rm->mixer_blks[i])
> > > continue;
> > >
> > > - lm_count = 0;
> > > + /*
> > > + * Clear the last bit to drop the previous primary mixer if
> > > + * fail to find its peer.
> >
> > Same here can we reword it to something like "Reset lm_count to an even
> > index. This will drop the previous primary mixer if ..."
>
> Will do.
>
> >
> > > + */
> > > + lm_count &= 0xfe;
> >
> > Nit: Can we directly clear the first bit instead of doing an 8-bit bitmask?
>
> Could you elaborate on it? Or you are suggesting to mask 0xFFFFFFFE?
I assume it is &= ~1
>
> - Jun
>
> >
> > Thanks,
> >
> > Jessica Zhang
> >
> > > lm_idx[lm_count] = i;
> > >
> > > if (!_dpu_rm_check_lm_and_get_connected_blks(rm, global_state,
> > >
> > > --
> > > 2.34.1
> > >
> >
--
With best wishes
Dmitry