Cursor plane updates have historically been fully async and mutliple
updates batched together for the next vsync. And userspace relies upon
that. Since implementing a full queue of async atomic updates is a bit
of work lets just recover the cursor specific behaviour with a hint
flag and some hacks to drop the vblank wait.
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
drivers/gpu/drm/drm_atomic_helper.c | 11 +++++++++++
include/drm/drm_crtc.h | 2 ++
2 files changed, 13 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c
b/drivers/gpu/drm/drm_atomic_helper.c
index 736ab924ddc9..a74a22db4dea 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -909,6 +909,11 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
if (!crtc->state->enable)
continue;
+ /* Legacy cursor ioctls are completely unsynced, and userspace
+ * relies on that (by doing tons of cursor updates). */
+ if (old_state->legacy_cursor_update)
+ continue;
+
if (!framebuffer_changed(dev, old_state, crtc))
continue;
@@ -1335,6 +1340,9 @@ retry:
if (ret != 0)
goto fail;
+ if (plane == crtc->cursor)
+ state->legacy_cursor_update = true;
+
/* Driver takes ownership of state on successful commit. */
return 0;
fail:
@@ -1410,6 +1418,9 @@ retry:
plane_state->src_h = 0;
plane_state->src_w = 0;
+ if (plane == plane->crtc->cursor)
+ state->legacy_cursor_update = true;
+
ret = drm_atomic_commit(state);
if (ret != 0)
goto fail;
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 4d3f3b874dd6..8b626ff3d3bd 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -929,6 +929,7 @@ struct drm_bridge {
* struct struct drm_atomic_state - the global state object for atomic updates
* @dev: parent DRM device
* @allow_modeset: allow full modeset
+ * @allow_modeset: hint to enforce legacy cursor ioctl semantics
* @planes: pointer to array of plane pointers
* @plane_states: pointer to array of plane states pointers
* @crtcs: pointer to array of CRTC pointers
@@ -941,6 +942,7 @@ struct drm_bridge {
struct drm_atomic_state {
struct drm_device *dev;
bool allow_modeset : 1;
+ bool legacy_cursor_update : 1;
struct drm_plane **planes;
struct drm_plane_state **plane_states;
struct drm_crtc **crtcs;
--
2.1.4
