Re: [PATCH 18/21] drm/msm/dpu: blend pipes by left and right
From: Dmitry Baryshkov
Date: Thu Aug 29 2024 - 07:51:54 EST
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.
> + 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?
> + }
> +
> + 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