Re: [PATCH 18/21] drm/msm/dpu: blend pipes by left and right

From: Jun Nie
Date: Tue Sep 03 2024 - 03:53:52 EST

Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> 于2024年8月29日周四 19:51写道：
>
> On Thu, 29 Aug 2024 at 13:21, Jun Nie <jun.nie@xxxxxxxxxx> wrote:
> >
> > Blend pipes by left and right. The first 2 pipes are for
> > left half screen and the later 2 pipes are for right in quad
> > pipe case.
> >
> > Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
> > ---
> > drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 13 +++++++++++--
> > drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 10 +++++++---
> > drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c | 19 +++++++++++++++++--
> > drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h | 4 +++-
> > 4 files changed, 38 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > index 3b3cd17976082..8fd56f8f2851f 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > @@ -574,8 +574,17 @@ static void _dpu_crtc_blend_setup(struct drm_crtc *crtc)
> > mixer[i].mixer_op_mode,
> > ctl->idx - CTL_0);
> >
> > - ctl->ops.setup_blendstage(ctl, mixer[i].hw_lm->idx,
> > - &stage_cfg);
> > + /*
> > + * call dpu_hw_ctl_setup_blendstage() to blend layers per stage cfg.
> > + * There is 4 mixers at most. The first 2 are for the left half, and
> > + * the later 2 are for the right half.
> > + */
> > + if (cstate->num_mixers == 4 && i >= 2)
> > + ctl->ops.setup_blendstage(ctl, mixer[i].hw_lm->idx,
> > + &stage_cfg, true);
> > + else
> > + ctl->ops.setup_blendstage(ctl, mixer[i].hw_lm->idx,
> > + &stage_cfg, false);
> > }
> > }
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > index 76793201b984e..5d927f23e35b2 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > @@ -2049,9 +2049,13 @@ static void dpu_encoder_helper_reset_mixers(struct dpu_encoder_phys *phys_enc)
> > if (phys_enc->hw_ctl->ops.update_pending_flush_mixer)
> > phys_enc->hw_ctl->ops.update_pending_flush_mixer(ctl, hw_mixer[i]->idx);
> >
> > - /* clear all blendstages */
> > - if (phys_enc->hw_ctl->ops.setup_blendstage)
> > - phys_enc->hw_ctl->ops.setup_blendstage(ctl, hw_mixer[i]->idx, NULL);
> > + /* clear all blendstages in both left and right */
> > + if (phys_enc->hw_ctl->ops.setup_blendstage) {
> > + phys_enc->hw_ctl->ops.setup_blendstage(ctl,
> > + hw_mixer[i]->idx, NULL, false);
> > + phys_enc->hw_ctl->ops.setup_blendstage(ctl,
> > + hw_mixer[i]->idx, NULL, true);
> > + }
> > }
> > }
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> > index 602dfad127c2a..2072d18520326 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> > @@ -478,12 +478,13 @@ static const struct ctl_blend_config ctl_blend_config[][2] = {
> > };
> >
> > static void dpu_hw_ctl_setup_blendstage(struct dpu_hw_ctl *ctx,
> > - enum dpu_lm lm, struct dpu_hw_stage_cfg *stage_cfg)
> > + enum dpu_lm lm, struct dpu_hw_stage_cfg *stage_cfg, bool right)
> > {
> > struct dpu_hw_blk_reg_map *c = &ctx->hw;
> > u32 mix, ext, mix_ext;
> > u32 mixercfg[5] = { 0 };
> > int i, j;
> > + int pipe_start, pipe_end;
> > int stages;
> > int pipes_per_stage;
> >
> > @@ -502,13 +503,27 @@ static void dpu_hw_ctl_setup_blendstage(struct dpu_hw_ctl *ctx,
> > if (!stage_cfg)
> > goto exit;
> >
> > + /*
> > + * For quad pipe case, blend pipes in right side separately. Otherwise,
> > + * all content is on the left half by defaut (no splitting case).
> > + */
> > + if (!right) {
>
> I think the approach to set PIPES_PER_STAGE to 4 is incorrect. It
> complicates the code too much. Instead please use two separate
> instances, each one representing a single LM pair and corresponding
> set of SW pipes. Yes, you'd have to iterate over them manually.
> However I think it's also going to make code simpler.

OK. I can explore this method.
>
> > + pipe_start = 0;
> > + pipe_end = pipes_per_stage == PIPES_PER_STAGE ? 2 : 1;
>
> pipe_end = pipes_per_stage
>
> > + } else {
> > + pipe_start = 2;
> > + pipe_end = PIPES_PER_STAGE;
>
> So, the right part always has 2 pipes? What if the
> DPU_MIXER_SOURCESPLIT isn't supported?

Yeah, the case is missed. It should be like this for the right half:
pipe_start = pipes_per_stage == PIPES_PER_STAGE ? 2 : 1;
pipe_end = pipes_per_stage == PIPES_PER_STAGE ? PIPES_PER_STAGE : 2;


>
>
> > + }
> > +
> > + DRM_DEBUG_ATOMIC("blend lm %d on the %s side\n", lm - LM_0,
> > + right ? "right" : "left");
> > for (i = 0; i <= stages; i++) {
> > /* overflow to ext register if 'i + 1 > 7' */
> > mix = (i + 1) & 0x7;
> > ext = i >= 7;
> > mix_ext = (i + 1) & 0xf;
> >
> > - for (j = 0 ; j < pipes_per_stage; j++) {
> > + for (j = pipe_start; j < pipe_end; j++) {
> > enum dpu_sspp_multirect_index rect_index =
> > stage_cfg->multirect_index[i][j];
> > enum dpu_sspp pipe = stage_cfg->stage[i][j];
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > index 557ec9a924f81..2dac7885fc5e7 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> > @@ -25,6 +25,8 @@ struct dpu_hw_ctl;
> > /**
> > * struct dpu_hw_stage_cfg - blending stage cfg
> > * @stage : SSPP_ID at each stage
> > + * The first 2 in PIPES_PER_STAGE(4) are for the first SSPP.
> > + * The 3rd/4th in PIPES_PER_STAGE(4) are for the 2nd SSPP.
> > * @multirect_index: index of the rectangle of SSPP.
> > */
> > struct dpu_hw_stage_cfg {
> > @@ -243,7 +245,7 @@ struct dpu_hw_ctl_ops {
> > * @cfg : blend stage configuration
> > */
> > void (*setup_blendstage)(struct dpu_hw_ctl *ctx,
> > - enum dpu_lm lm, struct dpu_hw_stage_cfg *cfg);
> > + enum dpu_lm lm, struct dpu_hw_stage_cfg *cfg, bool right);
> >
> > void (*set_active_pipes)(struct dpu_hw_ctl *ctx,
> > unsigned long *fetch_active);
> >
> > --
> > 2.34.1
> >
>
>
> --
> With best wishes
> Dmitry