[Intel-gfx] [PATCH v3 4/4] drm: Resurrect atomic rmfb code, v3

[Jani Nikula]

On Wed, 25 Jan 2017, Maarten Lankhorst <maarten.lankhorst at linux.intel.com> wrote:
> This was somehow lost between v3 and the merged version in Maarten's
> patch merged as:
>
> commit f2d580b9a8149735cbc4b59c4a8df60173658140
> Author: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Date:   Wed May 4 14:38:26 2016 +0200
>
>     drm/core: Do not preserve framebuffer on rmfb, v4.
>
> This introduces a slight behavioral change to rmfb. Instead of
> disabling a crtc when the primary plane is disabled, we try to
> preserve it.
>
> Apart from old versions of the vmwgfx xorg driver, there is
> nothing depending on rmfb disabling a crtc. Since vmwgfx is
> a legacy driver we can safely only disable the plane with atomic.
>
> If this commit is rejected by the driver then we will still fall
> back to the old behavior and turn off the crtc.
>
> v2:
> - Remove plane->fb assignment, done by drm_atomic_clean_old_fb.
> - Add WARN_ON when atomic_remove_fb fails.
> - Always call drm_atomic_state_put.
> v3:
> - Use drm_drv_uses_atomic_modeset
> - Handle the case where the first plane-disable-only commit fails
>   with -EINVAL. Some drivers do not support this, fall back to
>   disabling all crtc's in this case.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

Pushed to drm-misc-next-fixes, and sent the pull request to Dave. Thanks
for the patch.

BR,
Jani.


> ---
>  drivers/gpu/drm/drm_atomic.c        | 106 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc_internal.h |   1 +
>  drivers/gpu/drm/drm_framebuffer.c   |   7 +++
>  3 files changed, 114 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 723392fc98c8..c79ab8048435 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -2058,6 +2058,112 @@ static void complete_crtc_signaling(struct drm_device *dev,
>  	kfree(fence_state);
>  }
>  
> +int drm_atomic_remove_fb(struct drm_framebuffer *fb)
> +{
> +	struct drm_modeset_acquire_ctx ctx;
> +	struct drm_device *dev = fb->dev;
> +	struct drm_atomic_state *state;
> +	struct drm_plane *plane;
> +	struct drm_connector *conn;
> +	struct drm_connector_state *conn_state;
> +	int i, ret = 0;
> +	unsigned plane_mask, disable_crtcs = false;
> +
> +	state = drm_atomic_state_alloc(dev);
> +	if (!state)
> +		return -ENOMEM;
> +
> +	drm_modeset_acquire_init(&ctx, 0);
> +	state->acquire_ctx = &ctx;
> +
> +retry:
> +	plane_mask = 0;
> +	ret = drm_modeset_lock_all_ctx(dev, &ctx);
> +	if (ret)
> +		goto unlock;
> +
> +	drm_for_each_plane(plane, dev) {
> +		struct drm_plane_state *plane_state;
> +
> +		if (plane->state->fb != fb)
> +			continue;
> +
> +		plane_state = drm_atomic_get_plane_state(state, plane);
> +		if (IS_ERR(plane_state)) {
> +			ret = PTR_ERR(plane_state);
> +			goto unlock;
> +		}
> +
> +		/*
> +		 * Some drivers do not support keeping crtc active with the
> +		 * primary plane disabled. If we fail to commit with -EINVAL
> +		 * then we will try to perform the same commit but with all
> +		 * crtc's disabled for primary planes as well.
> +		 */
> +		if (disable_crtcs && plane_state->crtc->primary == plane) {
> +			struct drm_crtc_state *crtc_state;
> +
> +			crtc_state = drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
> +
> +			ret = drm_atomic_add_affected_connectors(state, plane_state->crtc);
> +			if (ret)
> +				goto unlock;
> +
> +			crtc_state->active = false;
> +			ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
> +			if (ret)
> +				goto unlock;
> +		}
> +
> +		drm_atomic_set_fb_for_plane(plane_state, NULL);
> +		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
> +		if (ret)
> +			goto unlock;
> +
> +		plane_mask |= BIT(drm_plane_index(plane));
> +
> +		plane->old_fb = plane->fb;
> +	}
> +
> +	/* This list is only not empty when disable_crtcs is set. */
> +	for_each_connector_in_state(state, conn, conn_state, i) {
> +		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
> +
> +		if (ret)
> +			goto unlock;
> +	}
> +
> +	if (plane_mask)
> +		ret = drm_atomic_commit(state);
> +
> +unlock:
> +	if (plane_mask)
> +		drm_atomic_clean_old_fb(dev, plane_mask, ret);
> +
> +	if (ret == -EDEADLK) {
> +		drm_modeset_backoff(&ctx);
> +		goto retry;
> +	}
> +
> +	drm_atomic_state_put(state);
> +
> +	if (ret == -EINVAL && !disable_crtcs) {
> +		disable_crtcs = true;
> +
> +		state = drm_atomic_state_alloc(dev);
> +		if (state) {
> +			state->acquire_ctx = &ctx;
> +			goto retry;
> +		}
> +		ret = -ENOMEM;
> +	}
> +
> +	drm_modeset_drop_locks(&ctx);
> +	drm_modeset_acquire_fini(&ctx);
> +
> +	return ret;
> +}
> +
>  int drm_mode_atomic_ioctl(struct drm_device *dev,
>  			  void *data, struct drm_file *file_priv)
>  {
> diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
> index 724c329186d5..d98a683d31d0 100644
> --- a/drivers/gpu/drm/drm_crtc_internal.h
> +++ b/drivers/gpu/drm/drm_crtc_internal.h
> @@ -184,6 +184,7 @@ int drm_atomic_get_property(struct drm_mode_object *obj,
>  			    struct drm_property *property, uint64_t *val);
>  int drm_mode_atomic_ioctl(struct drm_device *dev,
>  			  void *data, struct drm_file *file_priv);
> +int drm_atomic_remove_fb(struct drm_framebuffer *fb);
>  
>  
>  /* drm_plane.c */
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 588ccc3a2218..357b521bbdc3 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -773,6 +773,12 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
>  	 * in this manner.
>  	 */
>  	if (drm_framebuffer_read_refcount(fb) > 1) {
> +		if (drm_drv_uses_atomic_modeset(dev)) {
> +			int ret = drm_atomic_remove_fb(fb);
> +			WARN(ret, "atomic remove_fb failed with %i\n", ret);
> +			goto out;
> +		}
> +
>  		drm_modeset_lock_all(dev);
>  		/* remove from any CRTC */
>  		drm_for_each_crtc(crtc, dev) {
> @@ -790,6 +796,7 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
>  		drm_modeset_unlock_all(dev);
>  	}
>  
> +out:
>  	drm_framebuffer_unreference(fb);
>  }
>  EXPORT_SYMBOL(drm_framebuffer_remove);

-- 
Jani Nikula, Intel Open Source Technology Center