[PATCH v2 1/3] drm/atomic-helper: Export framebuffer_changed()

From: John Keeping
Date: Tue Jan 19 2016 - 05:48:12 EST


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>
---
Unchanged since v1.

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