On 25/02/2026 12:46, Yicong Hui wrote:
Add DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR ioctl flag for the
ioctls DRM_IOCTL_SYNCOBJ_WAIT and DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, which
will make them abort their wait and return the error code and its
associated syncobj.
Suggested-by: Christian König <[email protected]>
Suggested-by: Michel Dänzer <[email protected]>
Signed-off-by: Yicong Hui <[email protected]>
---
Changes in v3:
* Fixed inline comments by converting to multi-line comments in
accordance to kernel style guidelines.
* Used dma_fence_get_status to query error instead of getting it
directly.
drivers/gpu/drm/drm_syncobj.c | 27 +++++++++++++++++++++++----
include/uapi/drm/drm.h | 6 ++++++
2 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index b74e491f9d8b..2b23f638c1cc 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -1042,6 +1042,7 @@ static signed long drm_syncobj_array_wait_timeout(struct
drm_syncobj **syncobjs,
struct dma_fence *fence;
uint64_t *points;
uint32_t signaled_count, i;
+ int status;
if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
@@ -1139,6 +1140,14 @@ static signed long drm_syncobj_array_wait_timeout(struct
drm_syncobj **syncobjs,
if (!fence)
continue;
+ status = dma_fence_get_status(fence);
+ if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR) &&
status < 0) {
+ if (idx)
+ *idx = i;
+ timeout = status;
+ goto done_waiting;
+ }
+
if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
dma_fence_is_signaled(fence) ||
(!entries[i].fence_cb.func &&
@@ -1242,8 +1251,12 @@ static int drm_syncobj_array_wait(struct drm_device *dev,
wait->flags,
timeout, &first,
deadline);
I am calling this helper an unhelpful helper and was suggesting to get
rid of it:
https://lore.kernel.org/dri-devel/[email protected]/
"""
Helper which fails to consolidate the code and instead just forks into two
copies of the code based on a boolean parameter is not very helpful or
readable. Lets just remove it and proof in the pudding is the net smaller
code.
"""
Can we please nuke it?
- if (timeout < 0)
+ if (timeout < 0) {
+ if (wait->flags & DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR)
+ wait->first_signaled = first;
There can be timeout < 0 for reasons other than
DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR. Will 'first' contain a valid
value to return to userspace in that case? Will userspace even be able
to meaningfully distinguish between ioctl returning negative due some
random error, versus a fence error where otherwise nothing else failed?
+
return timeout;
+ }
wait->first_signaled = first;
} else {
timeout =
drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
@@ -1253,8 +1266,12 @@ static int drm_syncobj_array_wait(struct drm_device *dev,
timeline_wait->flags,
timeout, &first,
deadline);
- if (timeout < 0)
+ if (timeout < 0) {
+ if (timeline_wait->flags &
DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR)
+ timeline_wait->first_signaled = first;
+
return timeout;
+ }
timeline_wait->first_signaled = first;
}
return 0;
@@ -1332,7 +1349,8 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
- DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE |
+ DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR;
if (args->flags & ~possible_flags)
return -EINVAL;
@@ -1376,7 +1394,8 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device *dev,
void *data,
possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
- DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE |
+ DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR;
if (args->flags & ~possible_flags)
return -EINVAL;
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 213b4dc9b612..e998d9351525 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -977,6 +977,12 @@ struct drm_syncobj_transfer {
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2) /* wait for time point
to become available */
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE (1 << 3) /* set fence deadline
to deadline_nsec */
+/*
+ * As soon as any of the fences in the set have an error,
+ * abort waiting and return its error code. Index of this
+ * first failed fence is returned in first_signaled.
What else can be returned in first_signaled?
Regards,
Tvrtko
+ */
+#define DRM_SYNCOBJ_WAIT_FLAGS_ABORT_ON_ERROR (1 << 4)
struct drm_syncobj_wait {
__u64 handles;
/* absolute timeout */
