[weston, v12, 09/40] compositor-drm: Move repaint state application to flush

[Sergi Granell]

On Tue, 2017-09-26 at 18:15 +0100, Daniel Stone wrote:
> Split repaint into two stages, as implied by the grouped-repaint
> interface: drm_output_repaint generates the repaint state only, and
> drm_repaint_flush applies it.
> 
> This also moves DPMS into output state. Previously, the usual way to
> DPMS off was that repaint would be called and apply its state, followed
> by set_dpms being called afterwards to push the DPMS state separately.
> As this happens before the repaint_flush hook, with no change to DPMS we
> would set DPMS off, then immediately re-enable the output by posting the
> repaint. Not ideal.
> 
> Moving DPMS application at the same time complicates this patch, but I
> couldn't find a way to split it; if we keep set_dpms before begin_flush
> then we break DPMS off, or if we try to move DPMS to output state before
> using the repaint flush, we get stuck as the repaint hook generates an
> asynchronous state update, followed immediately by set_dpms generating a
> synchronous state update.
> 
> Signed-off-by: Daniel Stone <daniels at collabora.com>
> ---
>  libweston/compositor-drm.c | 313 ++++++++++++++++++++++++++++++++++-----
> ------
>  1 file changed, 240 insertions(+), 73 deletions(-)
> 
> diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
> index 530b0fd5..6c1c6881 100644
> --- a/libweston/compositor-drm.c
> +++ b/libweston/compositor-drm.c

[snip]

> @@ -1790,13 +1844,101 @@ drm_output_repaint(struct weston_output
> *output_base,
>  		}
>  	}
>  
> +	if (dpms_prop->prop_id && state->dpms != output->state_cur-
> >dpms) {
> +		ret = drmModeConnectorSetProperty(backend->drm.fd,
> +						  output->connector_id,
> +						  dpms_prop->prop_id,
> +						  state->dpms);
> +		if (ret) {
> +			weston_log("DRM: DPMS: failed property set for
> %s\n",
> +				   output->base.name);
> +		}
> +	}
> +
> +	drm_output_assign_state(state,
> DRM_OUTPUT_STATE_UPDATE_ASYNCHRONOUS);
> +
>  	return 0;
>  
>  err:
>  	output->cursor_view = NULL;
> -
>  	drm_output_state_free(state);
> +	return -1;
> +}
> +
> +static int
> +drm_pending_state_apply(struct drm_pending_state *pending_state)
> +{
> +	struct drm_backend *b = pending_state->backend;
> +	struct drm_output_state *output_state, *tmp;
> +	uint32_t *unused;
> +
> +	if (b->state_invalid) {
> +		/* If we need to reset all our state (e.g. because we've
> +		 * just started, or just been VT-switched in),
> explicitly
> +		 * disable all the CRTCs we aren't using. This also
> disables
> +		 * all connectors on these CRTCs, so we don't need to do
> that
> +		 * separately with the pre-atomic API. */
> +		wl_array_for_each(unused, &b->unused_crtcs)
> +			drmModeSetCrtc(b->drm.fd, *unused, 0, 0, 0,
> NULL, 0,
> +				       NULL);
> +	}
> +
> +	wl_list_for_each_safe(output_state, tmp, &pending_state-
> >output_list,
> +			      link) {
> +		struct drm_output *output = output_state->output;
> +		int ret;
> +
> +		ret = drm_output_apply_state(output_state);
> +		if (ret != 0) {
> +			weston_log("Couldn't apply state for output
> %s\n",
> +				   output->base.name);
> +		}
> +	}
> +
> +	b->state_invalid = false;
> +
> +	assert(wl_list_empty(&pending_state->output_list));
>  
> +	drm_pending_state_free(pending_state);
> +
> +	return 0;
> +}
> +
> +static int
> +drm_output_repaint(struct weston_output *output_base,
> +		   pixman_region32_t *damage,
> +		   void *repaint_data)
> +{
> +	struct drm_pending_state *pending_state = repaint_data;
> +	struct drm_output *output = to_drm_output(output_base);
> +	struct drm_output_state *state;
> +	struct drm_plane_state *scanout_state;
> +
> +	if (output->disable_pending || output->destroy_pending)
> +		goto err;

If this goes to 'err', 'drm_output_state_free' will be called
with an uninitialized 'state'.

> +
> +	assert(!output->state_last);
> +
> +	/* If planes have been disabled in the core, we might not have
> +	 * hit assign_planes at all, so might not have valid output
> state
> +	 * here. */
> +	state = drm_pending_state_get_output(pending_state, output);
> +	if (!state)
> +		state = drm_output_state_duplicate(output->state_cur,
> +						   pending_state,
> +						   DRM_OUTPUT_STATE_CLEA
> R_PLANES);
> +	state->dpms = WESTON_DPMS_ON;
> +
> +	drm_output_render(state, damage);
> +	scanout_state = drm_output_state_get_plane(state,
> +						   output-
> >scanout_plane);
> +	if (!scanout_state || !scanout_state->fb)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	drm_output_state_free(state);
>  	return -1;
>  }

[snip]