From: Erik Gilling konkers@android.com
If the two fences being merged contain sync_pts from the same timeline, those two pts will be collapsed into a single pt representing the latter of the two.
Cc: Maarten Lankhorst maarten.lankhorst@canonical.com Cc: Erik Gilling konkers@android.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Rob Clark robclark@gmail.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Greg KH gregkh@linuxfoundation.org Cc: dri-devel@lists.freedesktop.org Cc: Android Kernel Team kernel-team@android.com Signed-off-by: Erik Gilling konkers@android.com [jstultz: Whitespace fixes] Signed-off-by: John Stultz john.stultz@linaro.org --- drivers/staging/android/sync.c | 52 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index 2afbd69..6cb7c88 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -312,6 +312,56 @@ static int sync_fence_copy_pts(struct sync_fence *dst, struct sync_fence *src) return 0; }
+static int sync_fence_merge_pts(struct sync_fence *dst, struct sync_fence *src) +{ + struct list_head *src_pos, *dst_pos, *n; + + list_for_each(src_pos, &src->pt_list_head) { + struct sync_pt *src_pt = + container_of(src_pos, struct sync_pt, pt_list); + bool collapsed = false; + + list_for_each_safe(dst_pos, n, &dst->pt_list_head) { + struct sync_pt *dst_pt = + container_of(dst_pos, struct sync_pt, pt_list); + /* collapse two sync_pts on the same timeline + * to a single sync_pt that will signal at + * the later of the two + */ + if (dst_pt->parent == src_pt->parent) { + if (dst_pt->parent->ops->compare(dst_pt, src_pt) + == -1) { + struct sync_pt *new_pt = + sync_pt_dup(src_pt); + if (new_pt == NULL) + return -ENOMEM; + + new_pt->fence = dst; + list_replace(&dst_pt->pt_list, + &new_pt->pt_list); + sync_pt_activate(new_pt); + sync_pt_free(dst_pt); + } + collapsed = true; + break; + } + } + + if (!collapsed) { + struct sync_pt *new_pt = sync_pt_dup(src_pt); + + if (new_pt == NULL) + return -ENOMEM; + + new_pt->fence = dst; + list_add(&new_pt->pt_list, &dst->pt_list_head); + sync_pt_activate(new_pt); + } + } + + return 0; +} + static void sync_fence_free_pts(struct sync_fence *fence) { struct list_head *pos, *n; @@ -386,7 +436,7 @@ struct sync_fence *sync_fence_merge(const char *name, if (err < 0) goto err;
- err = sync_fence_copy_pts(fence, b); + err = sync_fence_merge_pts(fence, b); if (err < 0) goto err;