Re: [PATCH RFC v6 08/10] drm/msm/dpu: Allow NULL FBs in atomic commit

Dmitry Baryshkov
2023-09-24T10:29:09Z

On 29/08/2023 03:05, Jessica Zhang wrote:
> Since solid fill planes allow for a NULL framebuffer in a valid commit,
> add NULL framebuffer checks to atomic commit calls within DPU.
>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 9 ++++++-
> drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 41 ++++++++++++++++++++-----------
> 2 files changed, 34 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 8ce7586e2ddf..5e845510e8c1 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -451,6 +451,7 @@ static void _dpu_crtc_blend_setup_mixer(struct drm_crtc *crtc,
> struct drm_plane_state *state;
> struct dpu_crtc_state *cstate = to_dpu_crtc_state(crtc->state);
> struct dpu_plane_state *pstate = NULL;
> + const struct msm_format *fmt;
> struct dpu_format *format;
> struct dpu_hw_ctl *ctl = mixer->lm_ctl;
>
> @@ -470,7 +471,13 @@ static void _dpu_crtc_blend_setup_mixer(struct drm_crtc *crtc,
> pstate = to_dpu_plane_state(state);
> fb = state->fb;
>
> - format = to_dpu_format(msm_framebuffer_format(pstate->base.fb));
> + if (drm_plane_solid_fill_enabled(state))
> + fmt = dpu_get_msm_format(&_dpu_crtc_get_kms(crtc)->base,
> + DRM_FORMAT_ABGR8888, 0);
> + else
> + fmt = msm_framebuffer_format(pstate->base.fb);
> +
> + format = to_dpu_format(fmt);
>
> if (pstate->stage == DPU_STAGE_BASE && format->alpha_enable)
> bg_alpha_enable = true;
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> index c2aaaded07ed..114c803ff99b 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> @@ -837,8 +837,13 @@ static int dpu_plane_atomic_check(struct drm_plane *plane,
>
> pipe_cfg->dst_rect = new_plane_state->dst;
>
> - fb_rect.x2 = new_plane_state->fb->width;
> - fb_rect.y2 = new_plane_state->fb->height;
> + if (drm_plane_solid_fill_enabled(new_plane_state))
> + return 0;

This would skip all the width checks, dpu_plane_atomic_check_pipe(),
etc. Could you please confirm that all of those checks are irrelevant
for solid fill?

> +
> + if (new_plane_state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && new_plane_state->fb) {
> + fb_rect.x2 = new_plane_state->fb->width;
> + fb_rect.y2 = new_plane_state->fb->height;
> + }
>
> /* Ensure fb size is supported */
> if (drm_rect_width(&fb_rect) > MAX_IMG_WIDTH ||
> @@ -1082,21 +1087,32 @@ static void dpu_plane_sspp_atomic_update(struct drm_plane *plane)
> struct drm_crtc *crtc = state->crtc;
> struct drm_framebuffer *fb = state->fb;
> bool is_rt_pipe;
> - const struct dpu_format *fmt =
> - to_dpu_format(msm_framebuffer_format(fb));
> + const struct dpu_format *fmt;
> struct dpu_sw_pipe_cfg *pipe_cfg = &pstate->pipe_cfg;
> struct dpu_sw_pipe_cfg *r_pipe_cfg = &pstate->r_pipe_cfg;
> struct dpu_kms *kms = _dpu_plane_get_kms(&pdpu->base);
> struct msm_gem_address_space *aspace = kms->base.aspace;
> struct dpu_hw_fmt_layout layout;
> bool layout_valid = false;
> - int ret;
>
> - ret = dpu_format_populate_layout(aspace, fb, &layout);
> - if (ret)
> - DPU_ERROR_PLANE(pdpu, "failed to get format layout, %d\n", ret);
> - else
> - layout_valid = true;
> + if (state->pixel_source == DRM_PLANE_PIXEL_SOURCE_FB && fb) {
> + int ret;
> +
> + fmt = to_dpu_format(msm_framebuffer_format(fb));
> +
> + ret = dpu_format_populate_layout(aspace, fb, &layout);
> + if (ret)
> + DPU_ERROR_PLANE(pdpu, "failed to get format layout, %d\n", ret);
> + else
> + layout_valid = true;
> +
> + DPU_DEBUG_PLANE(pdpu, "FB[%u] " DRM_RECT_FP_FMT "->crtc%u " DRM_RECT_FMT
> + ", %4.4s ubwc %d\n", fb->base.id, DRM_RECT_FP_ARG(&state->src),
> + crtc->base.id, DRM_RECT_ARG(&state->dst),
> + (char *)&fmt->base.pixel_format, DPU_FORMAT_IS_UBWC(fmt));
> + } else {
> + fmt = dpu_get_dpu_format(DRM_FORMAT_ABGR8888);

#define DPU_SOLID_FILL_FORMAT ?

Also, I don't think that solid_fill planes consume bandwidth, so this
likely needs to be fixed too.

> + }
>
> pstate->pending = true;
>
> @@ -1104,11 +1120,6 @@ static void dpu_plane_sspp_atomic_update(struct drm_plane *plane)
> pstate->needs_qos_remap |= (is_rt_pipe != pdpu->is_rt_pipe);
> pdpu->is_rt_pipe = is_rt_pipe;
>
> - DPU_DEBUG_PLANE(pdpu, "FB[%u] " DRM_RECT_FP_FMT "->crtc%u " DRM_RECT_FMT
> - ", %4.4s ubwc %d\n", fb->base.id, DRM_RECT_FP_ARG(&state->src),
> - crtc->base.id, DRM_RECT_ARG(&state->dst),
> - (char *)&fmt->base.pixel_format, DPU_FORMAT_IS_UBWC(fmt));
> -
> dpu_plane_sspp_update_pipe(plane, pipe, pipe_cfg, fmt,
> drm_mode_vrefresh(&crtc->mode),
> layout_valid ? &layout : NULL);
>

--
With best wishes
Dmitry