[PATCH weston v12 36/40] compositor-drm: Add test-only mode to state application

Michael Tretter m.tretter at pengutronix.de
Tue Nov 14 11:21:33 UTC 2017


Hi Daniel,

On Tue, 26 Sep 2017 18:16:09 +0100, Daniel Stone wrote:
> The atomic API can allow us to test state before we apply it, to see if
> it will be valid. Add support for this, which we will later use in
> assign_planes to ensure our plane configuration is valid.
> 
> Signed-off-by: Daniel Stone <daniels at collabora.com>
> ---
>  libweston/compositor-drm.c | 180 +++++++++++++++++++++++++++++++++++----------
>  1 file changed, 141 insertions(+), 39 deletions(-)
> 
> diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
> index 7a720c34..e678fa7d 100644
> --- a/libweston/compositor-drm.c
> +++ b/libweston/compositor-drm.c
> @@ -1619,6 +1619,7 @@ drm_pending_state_get_output(struct drm_pending_state *pending_state,
>  }
>  
>  static int drm_pending_state_apply(struct drm_pending_state *state);
> +static int drm_pending_state_test(struct drm_pending_state *state);
>  
>  /**
>   * Mark a drm_output_state (the output's last state) as complete. This handles
> @@ -1728,12 +1729,15 @@ enum drm_output_propose_state_mode {
>  
>  static struct drm_plane_state *
>  drm_output_prepare_scanout_view(struct drm_output_state *output_state,
> -				struct weston_view *ev)
> +				struct weston_view *ev,
> +				enum drm_output_propose_state_mode mode)
>  {
>  	struct drm_output *output = output_state->output;
>  	struct drm_plane *scanout_plane = output->scanout_plane;
>  	struct drm_plane_state *state;
> +	struct drm_plane_state *state_old = NULL;
>  	struct drm_fb *fb;
> +	int ret;
>  
>  	fb = drm_fb_get_from_view(output_state, ev);
>  	if (!fb)
> @@ -1746,7 +1750,16 @@ drm_output_prepare_scanout_view(struct drm_output_state *output_state,
>  	}
>  
>  	state = drm_output_state_get_plane(output_state, scanout_plane);
> -	if (state->fb) {
> +
> +	/* Check if we've already placed a buffer on this plane; if there's a
> +	 * buffer there but it comes from GBM, then it's the result of
> +	 * drm_output_propose_state placing it here for testing purposes. */
> +	if (state->fb &&
> +	    (state->fb->type == BUFFER_GBM_SURFACE ||
> +	     state->fb->type == BUFFER_PIXMAN_DUMB)) {
> +		state_old = calloc(1, sizeof(*state_old));
> +		memcpy(state_old, state, sizeof(*state_old));
> +	} else if (state->fb) {
>  		drm_fb_unref(fb);
>  		return NULL;
>  	}
> @@ -1765,10 +1778,21 @@ drm_output_prepare_scanout_view(struct drm_output_state *output_state,
>  	    state->dest_h != (unsigned) output->base.current_mode->height)
>  		goto err;
>  
> +	if (mode == DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY)
> +		return state;
> +
> +	ret = drm_pending_state_test(output_state->pending_state);
> +	if (ret != 0)
> +		goto err;
> +
>  	return state;
>  
>  err:
> -	drm_plane_state_put_back(state);
> +	drm_plane_state_free(state, false);
> +	if (state_old) {
> +		wl_list_insert(&output_state->plane_list, &state_old->link);
> +		state_old->output_state = output_state;
> +	}
>  	return NULL;
>  }
>  
> @@ -1843,7 +1867,9 @@ drm_output_render(struct drm_output_state *state, pixman_region32_t *damage)
>  	 * want to render. */
>  	scanout_state = drm_output_state_get_plane(state,
>  						   output->scanout_plane);
> -	if (scanout_state->fb)
> +	if (scanout_state->fb &&
> +	    scanout_state->fb->type != BUFFER_GBM_SURFACE &&
> +	    scanout_state->fb->type != BUFFER_PIXMAN_DUMB)
>  		return;
>  
>  	if (!pixman_region32_not_empty(damage) &&
> @@ -1866,6 +1892,7 @@ drm_output_render(struct drm_output_state *state, pixman_region32_t *damage)
>  		return;
>  	}
>  
> +	drm_fb_unref(scanout_state->fb);
>  	scanout_state->fb = fb;
>  	scanout_state->output = output;
>  
> @@ -2245,8 +2272,14 @@ err:
>  	return -1;
>  }
>  
> +enum drm_pending_state_mode {
> +	DRM_PENDING_STATE_TEST,
> +	DRM_PENDING_STATE_APPLY,
> +};
> +
>  static int
> -drm_pending_state_apply_atomic(struct drm_pending_state *pending_state)
> +drm_pending_state_apply_atomic(struct drm_pending_state *pending_state,
> +			       enum drm_pending_state_mode mode)
>  {
>  	struct drm_backend *b = pending_state->backend;
>  	struct drm_output_state *output_state, *tmp;
> @@ -2386,8 +2419,15 @@ drm_pending_state_apply_atomic(struct drm_pending_state *pending_state)
>  		goto out;
>  	}
>  
> -	flags |= DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_NONBLOCK;
> +	if (mode == DRM_PENDING_STATE_TEST)
> +		flags |= DRM_MODE_ATOMIC_TEST_ONLY;
> +	else
> +		flags |= DRM_MODE_PAGE_FLIP_EVENT | DRM_MODE_ATOMIC_NONBLOCK;
>  	ret = drmModeAtomicCommit(b->drm.fd, req, flags, b);
> +
> +	if (mode == DRM_PENDING_STATE_TEST)
> +		return ret;

Leaks req and should drmModeAtomicFree(req) before returning or goto out.

Michael

> +
>  	if (ret != 0) {
>  		weston_log("atomic: couldn't commit new state: %m\n");
>  		goto out;
> @@ -2409,6 +2449,22 @@ out:
>  }
>  #endif
>  
> +static int
> +drm_pending_state_test(struct drm_pending_state *pending_state)
> +{
> +#ifdef HAVE_DRM_ATOMIC
> +	struct drm_backend *b = pending_state->backend;
> +
> +	if (b->atomic_modeset)
> +		return drm_pending_state_apply_atomic(pending_state,
> +						      DRM_PENDING_STATE_TEST);
> +#endif
> +
> +	/* We have no way to test state before application on the legacy
> +	 * modesetting API, so just claim it succeeded. */
> +	return 0;
> +}
> +
>  static int
>  drm_pending_state_apply(struct drm_pending_state *pending_state)
>  {
> @@ -2418,7 +2474,8 @@ drm_pending_state_apply(struct drm_pending_state *pending_state)
>  
>  #ifdef HAVE_DRM_ATOMIC
>  	if (b->atomic_modeset)
> -		return drm_pending_state_apply_atomic(pending_state);
> +		return drm_pending_state_apply_atomic(pending_state,
> +						      DRM_PENDING_STATE_APPLY);
>  #endif
>  
>  	if (b->state_invalid) {
> @@ -2720,7 +2777,8 @@ atomic_flip_handler(int fd, unsigned int frame, unsigned int sec,
>  
>  static struct drm_plane_state *
>  drm_output_prepare_overlay_view(struct drm_output_state *output_state,
> -				struct weston_view *ev)
> +				struct weston_view *ev,
> +				enum drm_output_propose_state_mode mode)
>  {
>  	struct drm_output *output = output_state->output;
>  	struct weston_compositor *ec = output->base.compositor;
> @@ -2729,9 +2787,7 @@ drm_output_prepare_overlay_view(struct drm_output_state *output_state,
>  	struct drm_plane_state *state = NULL;
>  	struct drm_fb *fb;
>  	unsigned int i;
> -
> -	if (b->sprites_are_broken)
> -		return NULL;
> +	int ret;
>  
>  	fb = drm_fb_get_from_view(output_state, ev);
>  	if (!fb)
> @@ -2763,29 +2819,37 @@ drm_output_prepare_overlay_view(struct drm_output_state *output_state,
>  			continue;
>  		}
>  
> -		break;
> -	}
> +		state->ev = ev;
> +		state->output = output;
> +		drm_plane_state_coords_for_view(state, ev);
> +		if (state->src_w != state->dest_w << 16 ||
> +		    state->src_h != state->dest_h << 16) {
> +			drm_plane_state_put_back(state);
> +			continue;
> +		}
>  
> -	/* No sprites available */
> -	if (!state) {
> -		drm_fb_unref(fb);
> -		return NULL;
> -	}
> +		/* We hold one reference for the lifetime of this function;
> +		 * from calling drm_fb_get_from_view, to the out label where
> +		 * we unconditionally drop the reference. So, we take another
> +		 * reference here to live within the state. */
> +		state->fb = drm_fb_ref(fb);
>  
> -	state->fb = fb;
> -	state->ev = ev;
> -	state->output = output;
> +		/* In planes-only mode, we don't have an incremental state to
> +		 * test against, so we just hope it'll work. */
> +		if (mode == DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY)
> +			goto out;
>  
> -	drm_plane_state_coords_for_view(state, ev);
> -	if (state->src_w != state->dest_w << 16 ||
> -	    state->src_h != state->dest_h << 16)
> -		goto err;
> +		ret = drm_pending_state_test(output_state->pending_state);
> +		if (ret == 0)
> +			goto out;
>  
> -	return state;
> +		drm_plane_state_put_back(state);
> +		state = NULL;
> +	}
>  
> -err:
> -	drm_plane_state_put_back(state);
> -	return NULL;
> +out:
> +	drm_fb_unref(fb);
> +	return state;
>  }
>  
>  /**
> @@ -2985,12 +3049,42 @@ drm_output_propose_state(struct weston_output *output_base,
>  	struct weston_view *ev;
>  	pixman_region32_t surface_overlap, renderer_region, occluded_region;
>  	bool renderer_ok = (mode != DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY);
> -	bool planes_ok = !b->sprites_are_broken;
> +	bool planes_ok = false;
> +	bool duplicate_renderer = false;
> +	int ret;
> +
> +	/* We can only propose planes if we're in plane-only mode (i.e. just
> +	 * get as much as possible into planes and test at the end), or mixed
> +	 * mode, where we have our previous renderer buffer (and it's broadly
> +	 * compatible) to test with. If we don't have these things, then we
> +	 * don't know whether or not the planes will work, so we conservatively
> +	 * fall back to just using the renderer. */
> +	if (mode == DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY) {
> +		if (b->sprites_are_broken)
> +			return NULL;
> +		planes_ok = true;
> +	} else if (output->scanout_plane->state_cur->fb) {
> +		struct drm_fb *scanout_fb =
> +			output->scanout_plane->state_cur->fb;
> +		if ((scanout_fb->type == BUFFER_GBM_SURFACE ||
> +		     scanout_fb->type == BUFFER_PIXMAN_DUMB) &&
> +		    scanout_fb->width == output_base->current_mode->width &&
> +		    scanout_fb->height == output_base->current_mode->height) {
> +			planes_ok = true;
> +			duplicate_renderer = true;
> +		}
> +	}
>  
>  	assert(!output->state_last);
>  	state = drm_output_state_duplicate(output->state_cur,
>  					   pending_state,
>  					   DRM_OUTPUT_STATE_CLEAR_PLANES);
> +	if (!planes_ok)
> +		return state;
> +
> +	if (duplicate_renderer)
> +		drm_plane_state_duplicate(state,
> +					  output->scanout_plane->state_cur);
>  
>  	/*
>  	 * Find a surface for each sprite in the output using some heuristics:
> @@ -3024,6 +3118,9 @@ drm_output_propose_state(struct weston_output *output_base,
>  		if (ev->output_mask != (1u << output->base.id))
>  			force_renderer = true;
>  
> +		if (!ev->surface->buffer_ref.buffer)
> +			force_renderer = true;
> +
>  		/* Ignore views we know to be totally occluded. */
>  		pixman_region32_init(&clipped_view);
>  		pixman_region32_intersect(&clipped_view,
> @@ -3059,17 +3156,13 @@ drm_output_propose_state(struct weston_output *output_base,
>  		 * cursors_are_broken flag. */
>  		if (!force_renderer && !b->cursors_are_broken)
>  			ps = drm_output_prepare_cursor_view(state, ev);
> -
>  		if (!planes_ok || !drm_view_is_opaque(ev))
>  			force_renderer = true;
>  
> -		if (!drm_view_is_opaque(ev))
> -			force_renderer = true;
> -
>  		if (!force_renderer && !ps)
> -			ps = drm_output_prepare_scanout_view(state, ev);
> +			ps = drm_output_prepare_scanout_view(state, ev, mode);
>  		if (!force_renderer && !ps)
> -			ps = drm_output_prepare_overlay_view(state, ev);
> +			ps = drm_output_prepare_overlay_view(state, ev, mode);
>  
>  		if (ps) {
>  			pixman_region32_union(&occluded_region,
> @@ -3077,8 +3170,6 @@ drm_output_propose_state(struct weston_output *output_base,
>  					      &clipped_view);
>  			pixman_region32_fini(&clipped_view);
>  			continue;
> -		}
> -
>  		if (!renderer_ok) {
>  			pixman_region32_fini(&clipped_view);
>  			goto err;
> @@ -3092,6 +3183,11 @@ drm_output_propose_state(struct weston_output *output_base,
>  	pixman_region32_fini(&renderer_region);
>  	pixman_region32_fini(&occluded_region);
>  
> +	/* Check to see if this state will actually work. */
> +	ret = drm_pending_state_test(state->pending_state);
> +	if (ret != 0)
> +		goto err;
> +
>  	return state;
>  
>  err:
> @@ -3112,8 +3208,14 @@ drm_assign_planes(struct weston_output *output_base, void *repaint_data)
>  	struct weston_view *ev;
>  	struct weston_plane *primary = &output_base->compositor->primary_plane;
>  
> +
>  	state = drm_output_propose_state(output_base, pending_state,
> -					 DRM_OUTPUT_PROPOSE_STATE_MIXED);
> +					 DRM_OUTPUT_PROPOSE_STATE_PLANES_ONLY);
> +	if (!state)
> +		state = drm_output_propose_state(output_base, pending_state,
> +						 DRM_OUTPUT_PROPOSE_STATE_MIXED);
> +
> +	assert(state);
>  
>  	wl_list_for_each(ev, &output_base->compositor->view_list, link) {
>  		struct drm_plane *target_plane = NULL;


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