[PATCH v11 10/12] drm/msm/dpu: support SSPP assignment for quad-pipe case
Dmitry Baryshkov
dmitry.baryshkov at oss.qualcomm.com
Tue Jun 3 10:21:46 UTC 2025
On Tue, Jun 03, 2025 at 03:10:09PM +0800, Jun Nie wrote:
> Currently, SSPPs are assigned to a maximum of two pipes. However,
> quad-pipe usage scenarios require four pipes and involve configuring
> two stages. In quad-pipe case, the first two pipes share a set of
> mixer configurations and enable multi-rect mode when certain
> conditions are met. The same applies to the subsequent two pipes.
>
> Assign SSPPs to the pipes in each stage using a unified method and
> to loop the stages accordingly.
>
> Signed-off-by: Jun Nie <jun.nie at linaro.org>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 148 +++++++++++++++++++-----------
> 1 file changed, 94 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> index 0bb153a71353ca9eaca138ebbee4cd699414771d..501b6a1bad4a1fee832f15efa7caec136a669da5 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> @@ -961,6 +961,33 @@ static int dpu_plane_is_multirect_parallel_capable(struct dpu_hw_sspp *sspp,
> dpu_plane_is_parallel_capable(pipe_cfg, fmt, max_linewidth);
> }
>
> +static bool dpu_plane_get_single_pipe(struct dpu_plane_state *pstate,
> + struct dpu_sw_pipe **single_pipe,
> + struct dpu_sw_pipe_cfg **single_pipe_cfg,
> + bool config_pipe)
Could you please describe, what does this function do? Why is it
returning the pipe or configuring a pipe?
> +{
> + int i, valid_pipe = 0;
> + struct dpu_sw_pipe *pipe;
> +
> + for (i = 0; i < PIPES_PER_PLANE; i++) {
> + if (drm_rect_width(&pstate->pipe_cfg[i].src_rect) != 0) {
> + valid_pipe++;
> + if (valid_pipe > 1)
> + return false;
> + *single_pipe = &pstate->pipe[i];
> + *single_pipe_cfg = &pstate->pipe_cfg[i];
> + } else {
> + if (!config_pipe)
> + continue;
> + pipe = &pstate->pipe[i];
> + pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> + pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> + pipe->sspp = NULL;
> + }
> + }
> +
> + return true;
> +}
>
> static int dpu_plane_atomic_check_sspp(struct drm_plane *plane,
> struct drm_atomic_state *state,
> @@ -1028,15 +1055,15 @@ static int dpu_plane_try_multirect_shared(struct dpu_plane_state *pstate,
> const struct msm_format *fmt,
> uint32_t max_linewidth)
> {
> - struct dpu_sw_pipe *pipe = &pstate->pipe[0];
> - struct dpu_sw_pipe *r_pipe = &pstate->pipe[1];
> - struct dpu_sw_pipe_cfg *pipe_cfg = &pstate->pipe_cfg[0];
> - struct dpu_sw_pipe *prev_pipe = &prev_adjacent_pstate->pipe[0];
> - struct dpu_sw_pipe_cfg *prev_pipe_cfg = &prev_adjacent_pstate->pipe_cfg[0];
> + struct dpu_sw_pipe *pipe, *prev_pipe;
> + struct dpu_sw_pipe_cfg *pipe_cfg, *prev_pipe_cfg;
> const struct msm_format *prev_fmt = msm_framebuffer_format(prev_adjacent_pstate->base.fb);
> u16 max_tile_height = 1;
>
> - if (prev_adjacent_pstate->pipe[1].sspp != NULL ||
> + if (!dpu_plane_get_single_pipe(pstate, &pipe, &pipe_cfg, true))
> + return false;
> +
> + if (!dpu_plane_get_single_pipe(prev_adjacent_pstate, &prev_pipe, &prev_pipe_cfg, false) ||
> prev_pipe->multirect_mode != DPU_SSPP_MULTIRECT_NONE)
> return false;
>
> @@ -1050,11 +1077,6 @@ static int dpu_plane_try_multirect_shared(struct dpu_plane_state *pstate,
> if (MSM_FORMAT_IS_UBWC(prev_fmt))
> max_tile_height = max(max_tile_height, prev_fmt->tile_height);
>
> - r_pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> - r_pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> -
> - r_pipe->sspp = NULL;
> -
> if (dpu_plane_is_parallel_capable(pipe_cfg, fmt, max_linewidth) &&
> dpu_plane_is_parallel_capable(prev_pipe_cfg, prev_fmt, max_linewidth) &&
> (pipe_cfg->dst_rect.x1 >= prev_pipe_cfg->dst_rect.x2 ||
> @@ -1183,6 +1205,51 @@ static int dpu_plane_virtual_atomic_check(struct drm_plane *plane,
> return 0;
> }
>
> +static int dpu_plane_try_multirect_in_stage(struct dpu_sw_pipe *pipe,
> + struct dpu_sw_pipe_cfg *pipe_cfg,
> + struct drm_plane_state *plane_state,
> + struct dpu_global_state *global_state,
> + struct drm_crtc *crtc,
> + struct dpu_rm_sspp_requirements *reqs)
> +{
> + struct drm_plane *plane = plane_state->plane;
> + struct dpu_kms *dpu_kms = _dpu_plane_get_kms(plane);
> + struct dpu_plane *pdpu = to_dpu_plane(plane);
> + struct dpu_sw_pipe *r_pipe = pipe + 1;
> + struct dpu_sw_pipe_cfg *r_pipe_cfg = pipe_cfg + 1;
> + int i;
> +
> + for (i = 0; i < PIPES_PER_STAGE; i++, pipe++, pipe_cfg++) {
> + if (drm_rect_width(&pipe_cfg->src_rect) == 0)
> + continue;
> +
> + pipe->sspp = dpu_rm_reserve_sspp(&dpu_kms->rm, global_state, crtc, reqs);
> + if (!pipe->sspp)
> + return -ENODEV;
> +
> + /*
> + * If current pipe is the first pipe in a stage, check
> + * multi-rect opportunity for the 2nd pipe in the stage.
> + * SSPP multi-rect mode cross stage is not supported.
> + */
> + if (!i &&
Unroll the loop. I think I've asked a similar change in the review of
the previous patch.
> + drm_rect_width(&r_pipe_cfg->src_rect) != 0 &&
> + dpu_plane_try_multirect_parallel(pipe, pipe_cfg, r_pipe, r_pipe_cfg,
> + pipe->sspp,
> + msm_framebuffer_format(plane_state->fb),
> + dpu_kms->catalog->caps->max_linewidth)) {
> + goto stage_assinged;
> + } else {
> + /* multirect is not possible, use dedicated SSPP */
> + pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> + pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> + }
> + }
> +
> +stage_assinged:
> + return 0;
> +}
> +
> static int dpu_plane_virtual_assign_resources(struct drm_crtc *crtc,
> struct dpu_global_state *global_state,
> struct drm_atomic_state *state,
> @@ -1195,11 +1262,9 @@ static int dpu_plane_virtual_assign_resources(struct drm_crtc *crtc,
> struct dpu_rm_sspp_requirements reqs;
> struct dpu_plane_state *pstate, *prev_adjacent_pstate;
> struct dpu_sw_pipe *pipe;
> - struct dpu_sw_pipe *r_pipe;
> struct dpu_sw_pipe_cfg *pipe_cfg;
> - struct dpu_sw_pipe_cfg *r_pipe_cfg;
> const struct msm_format *fmt;
> - int i;
> + int i, stage_id, ret;
>
> if (plane_state->crtc)
> crtc_state = drm_atomic_get_new_crtc_state(state,
> @@ -1209,11 +1274,6 @@ static int dpu_plane_virtual_assign_resources(struct drm_crtc *crtc,
> prev_adjacent_pstate = prev_adjacent_plane_state ?
> to_dpu_plane_state(prev_adjacent_plane_state) : NULL;
>
> - pipe = &pstate->pipe[0];
> - r_pipe = &pstate->pipe[1];
> - pipe_cfg = &pstate->pipe_cfg[0];
> - r_pipe_cfg = &pstate->pipe_cfg[1];
> -
> for (i = 0; i < PIPES_PER_PLANE; i++)
> pstate->pipe[i].sspp = NULL;
>
> @@ -1227,44 +1287,24 @@ static int dpu_plane_virtual_assign_resources(struct drm_crtc *crtc,
>
> reqs.rot90 = drm_rotation_90_or_270(plane_state->rotation);
>
> - if (drm_rect_width(&r_pipe_cfg->src_rect) == 0) {
> - if (!prev_adjacent_pstate ||
> - !dpu_plane_try_multirect_shared(pstate, prev_adjacent_pstate, fmt,
> - dpu_kms->catalog->caps->max_linewidth)) {
> - pipe->sspp = dpu_rm_reserve_sspp(&dpu_kms->rm, global_state, crtc, &reqs);
> - if (!pipe->sspp)
> - return -ENODEV;
> -
> - r_pipe->sspp = NULL;
> -
> - pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> - pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> -
> - r_pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> - r_pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> - }
> - } else {
> - pipe->sspp = dpu_rm_reserve_sspp(&dpu_kms->rm, global_state, crtc, &reqs);
> - if (!pipe->sspp)
> - return -ENODEV;
> -
> - if (!dpu_plane_try_multirect_parallel(pipe, pipe_cfg, r_pipe, r_pipe_cfg,
> - pipe->sspp,
> - msm_framebuffer_format(plane_state->fb),
> - dpu_kms->catalog->caps->max_linewidth)) {
> - /* multirect is not possible, use two SSPP blocks */
> - r_pipe->sspp = dpu_rm_reserve_sspp(&dpu_kms->rm, global_state, crtc, &reqs);
> - if (!r_pipe->sspp)
> - return -ENODEV;
> -
> - pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> - pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> + if (prev_adjacent_pstate &&
> + dpu_plane_try_multirect_shared(pstate, prev_adjacent_pstate, fmt,
> + dpu_kms->catalog->caps->max_linewidth)) {
And this needs to take care of LMs. prev_adjacent_pstate should be
per-stage, otherwise you can end up sharing the SSPPs between stages
(which is not allowed).
> + goto assigned;
> + }
>
> - r_pipe->multirect_index = DPU_SSPP_RECT_SOLO;
> - r_pipe->multirect_mode = DPU_SSPP_MULTIRECT_NONE;
> - }
> + for (stage_id = 0; stage_id < STAGES_PER_PLANE; stage_id++) {
> + pipe = &pstate->pipe[stage_id * PIPES_PER_STAGE];
> + pipe_cfg = &pstate->pipe_cfg[stage_id * PIPES_PER_STAGE];
> + ret = dpu_plane_try_multirect_in_stage(pipe, pipe_cfg,
> + plane_state,
> + global_state,
> + crtc, &reqs);
> + if (ret)
> + return ret;
> }
>
> +assigned:
> return dpu_plane_atomic_check_sspp(plane, state, crtc_state);
> }
>
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
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