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

[Dmitry Baryshkov]

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 at linaro.org>
> Signed-off-by: Jessica Zhang <quic_jesszhan at 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