Re: [PATCH 2/2] drm/msm/dpu: try multirect based on mdp clock limits

From: Dmitry Baryshkov
Date: Fri Sep 08 2023 - 19:30:24 EST


On Fri, 8 Sept 2023 at 21:55, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> It's certainly possible that for large resolutions a single DPU SSPP
> cannot process the image without exceeding the MDP clock limits but
> it can still process it in multirect mode because the source rectangles
> will get divided and can fall within the MDP clock limits.
>
> If the SSPP cannot process the image even in multirect mode, then it
> will be rejected in dpu_plane_atomic_check_pipe().
>
> Hence try using multirect for resolutions which cannot be processed
> by a single SSPP without exceeding the MDP clock limits.
>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> index 62dd9f9b4dce..85072328cd53 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> @@ -792,6 +792,7 @@ static int dpu_plane_atomic_check(struct drm_plane *plane,
> plane);
> int ret = 0, min_scale;
> struct dpu_plane *pdpu = to_dpu_plane(plane);
> + struct dpu_kms *kms = _dpu_plane_get_kms(&pdpu->base);
> struct dpu_plane_state *pstate = to_dpu_plane_state(new_plane_state);
> struct dpu_sw_pipe *pipe = &pstate->pipe;
> struct dpu_sw_pipe *r_pipe = &pstate->r_pipe;
> @@ -860,7 +861,8 @@ static int dpu_plane_atomic_check(struct drm_plane *plane,
>
> max_linewidth = pdpu->catalog->caps->max_linewidth;
>
> - if (drm_rect_width(&pipe_cfg->src_rect) > max_linewidth) {
> + if ((drm_rect_width(&pipe_cfg->src_rect) > max_linewidth) ||
> + _dpu_plane_calc_clk(&crtc_state->mode, pipe_cfg) > kms->perf.max_core_clk_rate) {

First, I think this should be an adjusted_mode too. And this probably
needs some more attention in the next few lines of code, since .e.g
the UBWC case also needs to be adjusted.

> /*
> * In parallel multirect case only the half of the usual width
> * is supported for tiled formats. If we are here, we know that
> --
> 2.40.1
>


--
With best wishes
Dmitry