[PATCH] drm/atomic: Add target_vblank support in atomic helpers (v2)

Daniel Vetter daniel at ffwll.ch
Mon Jan 9 09:59:27 UTC 2017


On Fri, Jan 06, 2017 at 03:39:40PM -0500, Andrey Grodzovsky wrote:
> Allows usage of the new page_flip_target hook for drivers implementing 
> the atomic path.
> Provides default atomic helper for the new hook.
> 
> v2:
> Update code sharing logic between exsiting and the new flip hooks.
> Improve kerneldoc.
> 
> Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky at amd.com>

Looks all reasonable, I think an ack from Alex that the amd side is in
shape too, and I'll pull this into drm-misc.

Thanks, Daniel

> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 133 ++++++++++++++++++++++++++++++------
>  include/drm/drm_atomic_helper.h     |   6 ++
>  include/drm/drm_crtc.h              |   9 +++
>  3 files changed, 127 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 583f47f..a4e5477 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -2733,6 +2733,44 @@ int drm_atomic_helper_resume(struct drm_device *dev,
>  }
>  EXPORT_SYMBOL(drm_atomic_helper_connector_set_property);
>  
> +static int page_flip_common(
> +				struct drm_atomic_state *state,
> +				struct drm_crtc *crtc,
> +				struct drm_framebuffer *fb,
> +				struct drm_pending_vblank_event *event)
> +{
> +	struct drm_plane *plane = crtc->primary;
> +	struct drm_plane_state *plane_state;
> +	struct drm_crtc_state *crtc_state;
> +	int ret = 0;
> +
> +	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> +	if (IS_ERR(crtc_state))
> +		return PTR_ERR(crtc_state);
> +
> +	crtc_state->event = event;
> +
> +	plane_state = drm_atomic_get_plane_state(state, plane);
> +	if (IS_ERR(plane_state))
> +		return PTR_ERR(plane_state);
> +
> +
> +	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
> +	if (ret != 0)
> +		return ret;
> +	drm_atomic_set_fb_for_plane(plane_state, fb);
> +
> +	/* Make sure we don't accidentally do a full modeset. */
> +	state->allow_modeset = false;
> +	if (!crtc_state->active) {
> +		DRM_DEBUG_ATOMIC("[CRTC:%d] disabled, rejecting legacy flip\n",
> +				 crtc->base.id);
> +		return -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
>  /**
>   * drm_atomic_helper_page_flip - execute a legacy page flip
>   * @crtc: DRM crtc
> @@ -2740,7 +2778,8 @@ int drm_atomic_helper_resume(struct drm_device *dev,
>   * @event: optional DRM event to signal upon completion
>   * @flags: flip flags for non-vblank sync'ed updates
>   *
> - * Provides a default page flip implementation using the atomic driver interface.
> + * Provides a default &drm_crtc_funcs.page_flip implementation
> + * using the atomic driver interface.
>   *
>   * Note that for now so called async page flips (i.e. updates which are not
>   * synchronized to vblank) are not supported, since the atomic interfaces have
> @@ -2748,6 +2787,9 @@ int drm_atomic_helper_resume(struct drm_device *dev,
>   *
>   * Returns:
>   * Returns 0 on success, negative errno numbers on failure.
> + *
> + * See also:
> + * drm_atomic_helper_page_flip_target()
>   */
>  int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
>  				struct drm_framebuffer *fb,
> @@ -2756,8 +2798,6 @@ int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
>  {
>  	struct drm_plane *plane = crtc->primary;
>  	struct drm_atomic_state *state;
> -	struct drm_plane_state *plane_state;
> -	struct drm_crtc_state *crtc_state;
>  	int ret = 0;
>  
>  	if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
> @@ -2768,35 +2808,86 @@ int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
>  		return -ENOMEM;
>  
>  	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
> +
>  retry:
> -	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> -	if (IS_ERR(crtc_state)) {
> -		ret = PTR_ERR(crtc_state);
> +	ret = page_flip_common(state, crtc, fb, event);
> +	if (ret != 0)
>  		goto fail;
> -	}
> -	crtc_state->event = event;
>  
> -	plane_state = drm_atomic_get_plane_state(state, plane);
> -	if (IS_ERR(plane_state)) {
> -		ret = PTR_ERR(plane_state);
> -		goto fail;
> -	}
> +	ret = drm_atomic_nonblocking_commit(state);
>  
> -	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
> +fail:
> +	if (ret == -EDEADLK)
> +		goto backoff;
> +
> +	drm_atomic_state_put(state);
> +	return ret;
> +
> +backoff:
> +	drm_atomic_state_clear(state);
> +	drm_atomic_legacy_backoff(state);
> +
> +	/*
> +	 * Someone might have exchanged the framebuffer while we dropped locks
> +	 * in the backoff code. We need to fix up the fb refcount tracking the
> +	 * core does for us.
> +	 */
> +	plane->old_fb = plane->fb;
> +
> +	goto retry;
> +}
> +EXPORT_SYMBOL(drm_atomic_helper_page_flip);
> +
> +/**
> + * drm_atomic_helper_page_flip_target - do page flip on target vblank period.
> + * @crtc: DRM crtc
> + * @fb: DRM framebuffer
> + * @event: optional DRM event to signal upon completion
> + * @flags: flip flags for non-vblank sync'ed updates
> + * @target: specifying the target vblank period when the flip to take effect
> + *
> + * Provides a default &drm_crtc_funcs.page_flip_target implementation.
> + * Similar to drm_atomic_helper_page_flip() with extra parameter to specify
> + * target vblank period to flip.
> + *
> + * Returns:
> + * Returns 0 on success, negative errno numbers on failure.
> + */
> +int drm_atomic_helper_page_flip_target(
> +				struct drm_crtc *crtc,
> +				struct drm_framebuffer *fb,
> +				struct drm_pending_vblank_event *event,
> +				uint32_t flags,
> +				uint32_t target)
> +{
> +	struct drm_plane *plane = crtc->primary;
> +	struct drm_atomic_state *state;
> +	struct drm_crtc_state *crtc_state;
> +	int ret = 0;
> +
> +	if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
> +		return -EINVAL;
> +
> +	state = drm_atomic_state_alloc(plane->dev);
> +	if (!state)
> +		return -ENOMEM;
> +
> +	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
> +
> +retry:
> +	ret = page_flip_common(state, crtc, fb, event);
>  	if (ret != 0)
>  		goto fail;
> -	drm_atomic_set_fb_for_plane(plane_state, fb);
>  
> -	/* Make sure we don't accidentally do a full modeset. */
> -	state->allow_modeset = false;
> -	if (!crtc_state->active) {
> -		DRM_DEBUG_ATOMIC("[CRTC:%d] disabled, rejecting legacy flip\n",
> -				 crtc->base.id);
> +	crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
> +	if (WARN_ON(!crtc_state)) {
>  		ret = -EINVAL;
>  		goto fail;
>  	}
> +	crtc_state->target_vblank = target;
>  
>  	ret = drm_atomic_nonblocking_commit(state);
> +
>  fail:
>  	if (ret == -EDEADLK)
>  		goto backoff;
> @@ -2817,7 +2908,7 @@ int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
>  
>  	goto retry;
>  }
> -EXPORT_SYMBOL(drm_atomic_helper_page_flip);
> +EXPORT_SYMBOL(drm_atomic_helper_page_flip_target);
>  
>  /**
>   * drm_atomic_helper_connector_dpms() - connector dpms helper implementation
> diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
> index 7ff92b0..b3b3abe 100644
> --- a/include/drm/drm_atomic_helper.h
> +++ b/include/drm/drm_atomic_helper.h
> @@ -124,6 +124,12 @@ int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
>  				struct drm_framebuffer *fb,
>  				struct drm_pending_vblank_event *event,
>  				uint32_t flags);
> +int drm_atomic_helper_page_flip_target(
> +				struct drm_crtc *crtc,
> +				struct drm_framebuffer *fb,
> +				struct drm_pending_vblank_event *event,
> +				uint32_t flags,
> +				uint32_t target);
>  int drm_atomic_helper_connector_dpms(struct drm_connector *connector,
>  				     int mode);
>  struct drm_encoder *
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 946672f..5c77c3f 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -157,6 +157,15 @@ struct drm_crtc_state {
>  	struct drm_property_blob *gamma_lut;
>  
>  	/**
> +	 * @target_vblank:
> +	 *
> +	 * Target vertical blank period when a page flip
> +	 * should take effect.
> +	 */
> +
> +	u32 target_vblank;
> +
> +	/**
>  	 * @event:
>  	 *
>  	 * Optional pointer to a DRM event to signal upon completion of the
> -- 
> 1.9.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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