This is a note to let you know that I've just added the patch titled
dma-buf: keep the signaling time of merged fences v3
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dma-buf-keep-the-signaling-time-of-merged-fences-v3.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f781f661e8c99b0cb34129f2e374234d61864e77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@xxxxxxx>
Date: Tue, 13 Jun 2023 10:09:20 +0200
Subject: dma-buf: keep the signaling time of merged fences v3
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From: Christian König <christian.koenig@xxxxxxx>
commit f781f661e8c99b0cb34129f2e374234d61864e77 upstream.
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: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Luben Tuikov <luben.tuikov@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230630120041.109216-1-christian.koenig@xxxxxxx
Cc: Jindong Yue <jindong.yue@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/dma-buf/dma-fence-unwrap.c | 26 ++++++++++++++++++++++----
drivers/dma-buf/dma-fence.c | 5 +++--
drivers/gpu/drm/drm_syncobj.c | 2 +-
include/linux/dma-fence.h | 2 +-
4 files changed, 27 insertions(+), 8 deletions(-)
--- a/drivers/dma-buf/dma-fence-unwrap.c
+++ b/drivers/dma-buf/dma-fence-unwrap.c
@@ -66,18 +66,36 @@ struct dma_fence *__dma_fence_unwrap_mer
{
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 @@ restart:
} while (tmp);
if (count == 0) {
- tmp = dma_fence_get_stub();
+ tmp = dma_fence_allocate_private_stub(ktime_get());
goto return_tmp;
}
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -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_pri
set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
&fence->flags);
- dma_fence_signal(fence);
+ dma_fence_signal_timestamp(fence, timestamp);
return fence;
}
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -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);
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -606,7 +606,7 @@ static inline signed long dma_fence_wait
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;
Patches currently in stable-queue which might be from christian.koenig@xxxxxxx are
queue-6.4/drm-ttm-never-consider-pinned-bos-for-eviction-swap.patch
queue-6.4/dma-buf-fix-an-error-pointer-vs-null-bug.patch
queue-6.4/dma-buf-keep-the-signaling-time-of-merged-fences-v3.patch
