Commit f781f661 authored by Christian König's avatar Christian König
Browse files

dma-buf: keep the signaling time of merged fences v3 



Some Android CTS is testing if the signaling time keeps consistent
during merges.

v2: use the current time if the fence is still in the signaling path and
the timestamp not yet available.
v3: improve comment, fix one more case to use the correct timestamp

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarLuben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230630120041.109216-1-christian.koenig@amd.com
parent 1c519980

drivers/dma-buf/dma-fence-unwrap.c

+22 −4
Original line number Diff line number Diff line
@@ -66,18 +66,36 @@ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, 
{

	struct dma_fence_array *result;

	struct dma_fence *tmp, **array;

	ktime_t timestamp;

	unsigned int i;

	size_t count;



	count = 0;

	timestamp = ns_to_ktime(0);

	for (i = 0; i < num_fences; ++i) {

		dma_fence_unwrap_for_each(tmp, &iter[i], fences[i])

			if (!dma_fence_is_signaled(tmp))

		dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) {

			if (!dma_fence_is_signaled(tmp)) {

				++count;

			} else if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT,

					    &tmp->flags)) {

				if (ktime_after(tmp->timestamp, timestamp))

					timestamp = tmp->timestamp;

			} else {

				/*

				 * Use the current time if the fence is

				 * currently signaling.

				 */

				timestamp = ktime_get();

			}

		}

	}



	/*

	 * If we couldn't find a pending fence just return a private signaled

	 * fence with the timestamp of the last signaled one.

	 */

	if (count == 0)

		return dma_fence_get_stub();

		return dma_fence_allocate_private_stub(timestamp);



	array = kmalloc_array(count, sizeof(*array), GFP_KERNEL);

	if (!array)
@@ -138,7 +156,7 @@ struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences, 
	} while (tmp);



	if (count == 0) {

		tmp = dma_fence_get_stub();

		tmp = dma_fence_allocate_private_stub(ktime_get());

		goto return_tmp;

	}

drivers/dma-buf/dma-fence.c

+3 −2
Original line number Diff line number Diff line
@@ -150,10 +150,11 @@ EXPORT_SYMBOL(dma_fence_get_stub); 


/**

 * dma_fence_allocate_private_stub - return a private, signaled fence

 * @timestamp: timestamp when the fence was signaled

 *

 * Return a newly allocated and signaled stub fence.

 */

struct dma_fence *dma_fence_allocate_private_stub(void)

struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp)

{

	struct dma_fence *fence;
@@ -169,7 +170,7 @@ struct dma_fence *dma_fence_allocate_private_stub(void) 
	set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,

		&fence->flags);



	dma_fence_signal(fence);

	dma_fence_signal_timestamp(fence, timestamp);



	return fence;

}

drivers/gpu/drm/drm_syncobj.c

+1 −1
Original line number Diff line number Diff line
@@ -353,7 +353,7 @@ EXPORT_SYMBOL(drm_syncobj_replace_fence); 
 */

static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)

{

	struct dma_fence *fence = dma_fence_allocate_private_stub();

	struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());



	if (IS_ERR(fence))

		return PTR_ERR(fence);

include/linux/dma-fence.h

+1 −1
Original line number Diff line number Diff line
@@ -606,7 +606,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) 
void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline);



struct dma_fence *dma_fence_get_stub(void);

struct dma_fence *dma_fence_allocate_private_stub(void);

struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp);

u64 dma_fence_context_alloc(unsigned num);



extern const struct dma_fence_ops dma_fence_array_ops;