Re: [PATCH 1/3] drm/atomic-helper: Export framebuffer_changed()

From: Daniel Vetter
Date: Thu Jan 14 2016 - 09:56:39 EST


On Thu, Jan 14, 2016 at 02:39:40PM +0000, John Keeping wrote:
> The Rockchip driver cannot use drm_atomic_helper_wait_for_vblanks()
> because it has hardware counters for neither vblanks nor scanlines.
>
> In order to simplify re-implementing the functionality for this driver,
> export the framebuffer_changed() helper so it can be reused.
>
> Signed-off-by: John Keeping <john@xxxxxxxxxxxx>

Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> And since I don't
expect anyone else to need this anytime soon probably best you just pull
this in through rockchip trees.

Cheers, Daniel

> ---
> drivers/gpu/drm/drm_atomic_helper.c | 24 ++++++++++++++++++++----
> include/drm/drm_atomic_helper.h | 4 ++++
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 268d37f..7449293 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -948,9 +948,23 @@ static void wait_for_fences(struct drm_device *dev,
> }
> }
>
> -static bool framebuffer_changed(struct drm_device *dev,
> - struct drm_atomic_state *old_state,
> - struct drm_crtc *crtc)
> +/**
> + * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
> + * @dev: DRM device
> + * @old_state: atomic state object with old state structures
> + * @crtc: DRM crtc
> + *
> + * Checks whether the framebuffer used for this CRTC changes as a result of
> + * the atomic update. This is useful for drivers which cannot use
> + * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
> + * functionality.
> + *
> + * Returns:
> + * true if the framebuffer changed.
> + */
> +bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
> + struct drm_atomic_state *old_state,
> + struct drm_crtc *crtc)
> {
> struct drm_plane *plane;
> struct drm_plane_state *old_plane_state;
> @@ -967,6 +981,7 @@ static bool framebuffer_changed(struct drm_device *dev,
>
> return false;
> }
> +EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);
>
> /**
> * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
> @@ -1001,7 +1016,8 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
> if (old_state->legacy_cursor_update)
> continue;
>
> - if (!framebuffer_changed(dev, old_state, crtc))
> + if (!drm_atomic_helper_framebuffer_changed(dev,
> + old_state, crtc))
> continue;
>
> ret = drm_crtc_vblank_get(crtc);
> diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
> index a286cce..74fce78 100644
> --- a/include/drm/drm_atomic_helper.h
> +++ b/include/drm/drm_atomic_helper.h
> @@ -42,6 +42,10 @@ int drm_atomic_helper_commit(struct drm_device *dev,
> struct drm_atomic_state *state,
> bool async);
>
> +bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
> + struct drm_atomic_state *old_state,
> + struct drm_crtc *crtc);
> +
> void drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
> struct drm_atomic_state *old_state);
>
> --
> 2.7.0.226.gfe986fe
>

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