drm: writeback: Add out-fences for writeback connectors
Add the WRITEBACK_OUT_FENCE_PTR property to writeback connectors, to
enable userspace to get a fence which will signal once the writeback is
complete. It is not allowed to request an out-fence without a
framebuffer attached to the connector.
A timeline is added to drm_writeback_connector for use by the writeback
out-fences.
In the case of a commit failure or DRM_MODE_ATOMIC_TEST_ONLY, the fence
is set to -1.
Changes from v2:
- Rebase onto Gustavo Padovan's v9 explicit sync series
- Change out_fence_ptr type to s32 __user *
- Set *out_fence_ptr to -1 in drm_atomic_connector_set_property
- Store fence in drm_writeback_job
Gustavo Padovan:
- Move out_fence_ptr out of connector_state
- Signal fence from drm_writeback_signal_completion instead of
in driver directly
Changes from v3:
- Rebase onto commit 7e9081c5aac7 ("drm/fence: fix memory overwrite
when setting out_fence fd") (change out_fence_ptr to s32 __user *,
for real this time.)
- Update documentation around WRITEBACK_OUT_FENCE_PTR
Signed-off-by: Brian Starkey <brian.starkey@arm.com>
[rebased and fixed conflicts]
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/229036/
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 8254521..da9d95a 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -160,6 +160,14 @@ struct __drm_crtcs_state {
struct __drm_connnectors_state {
struct drm_connector *ptr;
struct drm_connector_state *state, *old_state, *new_state;
+ /**
+ * @out_fence_ptr:
+ *
+ * User-provided pointer which the kernel uses to return a sync_file
+ * file descriptor. Used by writeback connectors to signal completion of
+ * the writeback.
+ */
+ s32 __user *out_fence_ptr;
};
struct drm_private_obj;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 716c3a0..14ab58a 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -441,10 +441,10 @@ struct drm_connector_state {
/**
* @writeback_job: Writeback job for writeback connectors
*
- * Holds the framebuffer for a writeback connector. As the writeback
- * completion may be asynchronous to the normal commit cycle, the
- * writeback job lifetime is managed separately from the normal atomic
- * state by this object.
+ * Holds the framebuffer and out-fence for a writeback connector. As
+ * the writeback completion may be asynchronous to the normal commit
+ * cycle, the writeback job lifetime is managed separately from the
+ * normal atomic state by this object.
*
* See also: drm_writeback_queue_job() and
* drm_writeback_signal_completion()
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 5f24329..f4a173c 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -798,6 +798,14 @@ struct drm_mode_config {
* See also: drm_writeback_connector_init()
*/
struct drm_property *writeback_pixel_formats_property;
+ /**
+ * @writeback_out_fence_ptr_property: Property for writeback connectors,
+ * fd pointer representing the outgoing fences for a writeback
+ * connector. Userspace should provide a pointer to a value of type s32,
+ * and then cast that pointer to u64.
+ * See also: drm_writeback_connector_init()
+ */
+ struct drm_property *writeback_out_fence_ptr_property;
/* dumb ioctl parameters */
uint32_t preferred_depth, prefer_shadow;
diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
index 17cd1fe..a10fe55 100644
--- a/include/drm/drm_writeback.h
+++ b/include/drm/drm_writeback.h
@@ -50,6 +50,32 @@ struct drm_writeback_connector {
* drm_writeback_signal_completion()
*/
struct list_head job_queue;
+
+ /**
+ * @fence_context:
+ *
+ * timeline context used for fence operations.
+ */
+ unsigned int fence_context;
+ /**
+ * @fence_lock:
+ *
+ * spinlock to protect the fences in the fence_context.
+ */
+ spinlock_t fence_lock;
+ /**
+ * @fence_seqno:
+ *
+ * Seqno variable used as monotonic counter for the fences
+ * created on the connector's timeline.
+ */
+ unsigned long fence_seqno;
+ /**
+ * @timeline_name:
+ *
+ * The name of the connector's fence timeline.
+ */
+ char timeline_name[32];
};
struct drm_writeback_job {
@@ -75,6 +101,13 @@ struct drm_writeback_job {
* directly, use drm_atomic_set_writeback_fb_for_connector()
*/
struct drm_framebuffer *fb;
+
+ /**
+ * @out_fence:
+ *
+ * Fence which will signal once the writeback has completed
+ */
+ struct dma_fence *out_fence;
};
int drm_writeback_connector_init(struct drm_device *dev,
@@ -87,5 +120,11 @@ void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
struct drm_writeback_job *job);
void drm_writeback_cleanup_job(struct drm_writeback_job *job);
-void drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector);
+
+void
+drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
+ int status);
+
+struct dma_fence *
+drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector);
#endif
