* [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain"
@ 2026-02-23 19:57 Christian König
2026-02-23 20:18 ` Matthew Brost
2026-02-23 20:45 ` ✗ i915.CI.BAT: failure for " Patchwork
0 siblings, 2 replies; 4+ messages in thread
From: Christian König @ 2026-02-23 19:57 UTC (permalink / raw)
To: matthew.brost; +Cc: dri-devel, intel-gfx
This reverts commit a408c0ca0c411ca1ead995bdae3112a806c87556.
This causes a lockdep splat. Not really the right fix, but changing this
is more work than expected.
Signed-off-by: Christian König <christian.koenig@amd.com>
---
drivers/dma-buf/dma-fence-chain.c | 3 ++-
include/linux/dma-fence-chain.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index a707792b6025..a8a90acf4f34 100644
--- a/drivers/dma-buf/dma-fence-chain.c
+++ b/drivers/dma-buf/dma-fence-chain.c
@@ -245,6 +245,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
struct dma_fence_chain *prev_chain = to_dma_fence_chain(prev);
uint64_t context;
+ spin_lock_init(&chain->lock);
rcu_assign_pointer(chain->prev, prev);
chain->fence = fence;
chain->prev_seqno = 0;
@@ -260,7 +261,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
seqno = max(prev->seqno, seqno);
}
- dma_fence_init64(&chain->base, &dma_fence_chain_ops, NULL,
+ dma_fence_init64(&chain->base, &dma_fence_chain_ops, &chain->lock,
context, seqno);
/*
diff --git a/include/linux/dma-fence-chain.h b/include/linux/dma-fence-chain.h
index df3beadf1515..5cd3ba53b4a1 100644
--- a/include/linux/dma-fence-chain.h
+++ b/include/linux/dma-fence-chain.h
@@ -46,6 +46,7 @@ struct dma_fence_chain {
*/
struct irq_work work;
};
+ spinlock_t lock;
};
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain"
2026-02-23 19:57 [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain" Christian König
@ 2026-02-23 20:18 ` Matthew Brost
2026-02-24 15:27 ` Matthew Brost
2026-02-23 20:45 ` ✗ i915.CI.BAT: failure for " Patchwork
1 sibling, 1 reply; 4+ messages in thread
From: Matthew Brost @ 2026-02-23 20:18 UTC (permalink / raw)
To: Christian König; +Cc: dri-devel, intel-gfx
On Mon, Feb 23, 2026 at 08:57:05PM +0100, Christian König wrote:
> This reverts commit a408c0ca0c411ca1ead995bdae3112a806c87556.
>
> This causes a lockdep splat. Not really the right fix, but changing this
> is more work than expected.
>
I think dma-fence-arrays will have the same issue.
Can’t we just assign a lockdep key for chains and arrays?
Typing as fast as I could, I came up with this, and it seems to work:
diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
index cd970eceaefb..d5cce24dca5b 100644
--- a/drivers/dma-buf/dma-fence-array.c
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -200,6 +200,10 @@ void dma_fence_array_init(struct dma_fence_array *array,
u64 context, unsigned seqno,
bool signal_on_any)
{
+#if IS_ENABLED(CONFIG_PROVE_LOCKING)
+ static struct lock_class_key dma_fence_array_lock_key;
+#endif
+
WARN_ON(!num_fences || !fences);
array->num_fences = num_fences;
@@ -208,6 +212,10 @@ void dma_fence_array_init(struct dma_fence_array *array,
seqno);
init_irq_work(&array->work, irq_dma_fence_array_work);
+#if IS_ENABLED(CONFIG_PROVE_LOCKING)
+ lockdep_set_class(&array->base.inline_lock, &dma_fence_array_lock_key);
+#endif
+
atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
array->fences = fences;
diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index a707792b6025..aa144b8c3534 100644
--- a/drivers/dma-buf/dma-fence-chain.c
+++ b/drivers/dma-buf/dma-fence-chain.c
@@ -242,6 +242,9 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
struct dma_fence *fence,
uint64_t seqno)
{
+#if IS_ENABLED(CONFIG_PROVE_LOCKING)
+ static struct lock_class_key dma_fence_chain_lock_key;
+#endif
struct dma_fence_chain *prev_chain = to_dma_fence_chain(prev);
uint64_t context;
@@ -263,6 +266,10 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
dma_fence_init64(&chain->base, &dma_fence_chain_ops, NULL,
context, seqno);
+#if IS_ENABLED(CONFIG_PROVE_LOCKING)
+ lockdep_set_class(&chain->base.inline_lock, &dma_fence_chain_lock_key);
+#endif
+
/*
* Chaining dma_fence_chain container together is only allowed through
* the prev fence and not through the contained fence.
Matt
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
> drivers/dma-buf/dma-fence-chain.c | 3 ++-
> include/linux/dma-fence-chain.h | 1 +
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
> index a707792b6025..a8a90acf4f34 100644
> --- a/drivers/dma-buf/dma-fence-chain.c
> +++ b/drivers/dma-buf/dma-fence-chain.c
> @@ -245,6 +245,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> struct dma_fence_chain *prev_chain = to_dma_fence_chain(prev);
> uint64_t context;
>
> + spin_lock_init(&chain->lock);
> rcu_assign_pointer(chain->prev, prev);
> chain->fence = fence;
> chain->prev_seqno = 0;
> @@ -260,7 +261,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> seqno = max(prev->seqno, seqno);
> }
>
> - dma_fence_init64(&chain->base, &dma_fence_chain_ops, NULL,
> + dma_fence_init64(&chain->base, &dma_fence_chain_ops, &chain->lock,
> context, seqno);
>
> /*
> diff --git a/include/linux/dma-fence-chain.h b/include/linux/dma-fence-chain.h
> index df3beadf1515..5cd3ba53b4a1 100644
> --- a/include/linux/dma-fence-chain.h
> +++ b/include/linux/dma-fence-chain.h
> @@ -46,6 +46,7 @@ struct dma_fence_chain {
> */
> struct irq_work work;
> };
> + spinlock_t lock;
> };
>
>
> --
> 2.43.0
>
^ permalink raw reply related [flat|nested] 4+ messages in thread
* ✗ i915.CI.BAT: failure for dma-buf: revert "use inline lock for the dma-fence-chain"
2026-02-23 19:57 [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain" Christian König
2026-02-23 20:18 ` Matthew Brost
@ 2026-02-23 20:45 ` Patchwork
1 sibling, 0 replies; 4+ messages in thread
From: Patchwork @ 2026-02-23 20:45 UTC (permalink / raw)
To: Christian König; +Cc: intel-gfx
[-- Attachment #1: Type: text/plain, Size: 5787 bytes --]
== Series Details ==
Series: dma-buf: revert "use inline lock for the dma-fence-chain"
URL : https://patchwork.freedesktop.org/series/162008/
State : failure
== Summary ==
CI Bug Log - changes from CI_DRM_18022 -> Patchwork_162008v1
====================================================
Summary
-------
**FAILURE**
Serious unknown changes coming with Patchwork_162008v1 absolutely need to be
verified manually.
If you think the reported changes have nothing to do with the changes
introduced in Patchwork_162008v1, please notify your bug team (I915-ci-infra@lists.freedesktop.org) to allow them
to document this new failure mode, which will reduce false positives in CI.
External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/index.html
Participating hosts (43 -> 41)
------------------------------
Missing (2): bat-dg2-13 fi-snb-2520m
Possible new issues
-------------------
Here are the unknown changes that may have been introduced in Patchwork_162008v1:
### IGT changes ###
#### Possible regressions ####
* igt@i915_selftest@live:
- bat-arls-5: [PASS][1] -> [TIMEOUT][2] +1 other test timeout
[1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-5/igt@i915_selftest@live.html
[2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-5/igt@i915_selftest@live.html
* igt@kms_pipe_crc_basic@hang-read-crc@pipe-b-dp-3:
- bat-arls-5: [PASS][3] -> [DMESG-WARN][4] +3 other tests dmesg-warn
[3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-5/igt@kms_pipe_crc_basic@hang-read-crc@pipe-b-dp-3.html
[4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-5/igt@kms_pipe_crc_basic@hang-read-crc@pipe-b-dp-3.html
* igt@kms_pipe_crc_basic@read-crc:
- fi-cfl-8109u: [PASS][5] -> [DMESG-WARN][6] +48 other tests dmesg-warn
[5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/fi-cfl-8109u/igt@kms_pipe_crc_basic@read-crc.html
[6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/fi-cfl-8109u/igt@kms_pipe_crc_basic@read-crc.html
Known issues
------------
Here are the changes found in Patchwork_162008v1 that come from known issues:
### IGT changes ###
#### Issues hit ####
* igt@i915_module_load@reload:
- bat-arls-6: [PASS][7] -> [DMESG-WARN][8] ([i915#15738]) +36 other tests dmesg-warn
[7]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-6/igt@i915_module_load@reload.html
[8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-6/igt@i915_module_load@reload.html
* igt@i915_selftest@live@evict:
- bat-arls-6: [PASS][9] -> [DMESG-FAIL][10] ([i915#15738])
[9]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-6/igt@i915_selftest@live@evict.html
[10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-6/igt@i915_selftest@live@evict.html
* igt@i915_selftest@live@gem_contexts:
- bat-arls-6: [PASS][11] -> [INCOMPLETE][12] ([i915#15738])
[11]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-6/igt@i915_selftest@live@gem_contexts.html
[12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-6/igt@i915_selftest@live@gem_contexts.html
* igt@i915_selftest@live@sanitycheck:
- bat-arls-5: [PASS][13] -> [DMESG-WARN][14] ([i915#15738]) +17 other tests dmesg-warn
[13]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-5/igt@i915_selftest@live@sanitycheck.html
[14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-5/igt@i915_selftest@live@sanitycheck.html
* igt@i915_selftest@live@workarounds:
- bat-dg2-14: [PASS][15] -> [DMESG-FAIL][16] ([i915#12061]) +1 other test dmesg-fail
[15]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-dg2-14/igt@i915_selftest@live@workarounds.html
[16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-dg2-14/igt@i915_selftest@live@workarounds.html
* igt@kms_hdmi_inject@inject-audio:
- fi-tgl-1115g4: [PASS][17] -> [SKIP][18] ([i915#13030])
[17]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/fi-tgl-1115g4/igt@kms_hdmi_inject@inject-audio.html
[18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/fi-tgl-1115g4/igt@kms_hdmi_inject@inject-audio.html
#### Warnings ####
* igt@i915_selftest@live:
- bat-arls-6: [DMESG-FAIL][19] ([i915#12061]) -> [INCOMPLETE][20] ([i915#15738])
[19]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-6/igt@i915_selftest@live.html
[20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-6/igt@i915_selftest@live.html
* igt@i915_selftest@live@workarounds:
- bat-arls-6: [DMESG-FAIL][21] ([i915#12061]) -> [DMESG-WARN][22] ([i915#15738])
[21]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_18022/bat-arls-6/igt@i915_selftest@live@workarounds.html
[22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/bat-arls-6/igt@i915_selftest@live@workarounds.html
[i915#12061]: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12061
[i915#13030]: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13030
[i915#15738]: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15738
Build changes
-------------
* Linux: CI_DRM_18022 -> Patchwork_162008v1
CI-20190529: 20190529
CI_DRM_18022: 45a3045fc0dc46a893cb8bbe304afafd4120c904 @ git://anongit.freedesktop.org/gfx-ci/linux
IGT_8765: 8765
Patchwork_162008v1: 45a3045fc0dc46a893cb8bbe304afafd4120c904 @ git://anongit.freedesktop.org/gfx-ci/linux
== Logs ==
For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_162008v1/index.html
[-- Attachment #2: Type: text/html, Size: 7219 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain"
2026-02-23 20:18 ` Matthew Brost
@ 2026-02-24 15:27 ` Matthew Brost
0 siblings, 0 replies; 4+ messages in thread
From: Matthew Brost @ 2026-02-24 15:27 UTC (permalink / raw)
To: Christian König; +Cc: dri-devel, intel-gfx
On Mon, Feb 23, 2026 at 12:18:38PM -0800, Matthew Brost wrote:
> On Mon, Feb 23, 2026 at 08:57:05PM +0100, Christian König wrote:
> > This reverts commit a408c0ca0c411ca1ead995bdae3112a806c87556.
> >
> > This causes a lockdep splat. Not really the right fix, but changing this
> > is more work than expected.
> >
Ping - this is blocking our CI so if we can figure out the best way to
move forward soon, it is would be helpful.
Mstt
>
> I think dma-fence-arrays will have the same issue.
>
> Can’t we just assign a lockdep key for chains and arrays?
>
> Typing as fast as I could, I came up with this, and it seems to work:
>
> diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
> index cd970eceaefb..d5cce24dca5b 100644
> --- a/drivers/dma-buf/dma-fence-array.c
> +++ b/drivers/dma-buf/dma-fence-array.c
> @@ -200,6 +200,10 @@ void dma_fence_array_init(struct dma_fence_array *array,
> u64 context, unsigned seqno,
> bool signal_on_any)
> {
> +#if IS_ENABLED(CONFIG_PROVE_LOCKING)
> + static struct lock_class_key dma_fence_array_lock_key;
> +#endif
> +
> WARN_ON(!num_fences || !fences);
>
> array->num_fences = num_fences;
> @@ -208,6 +212,10 @@ void dma_fence_array_init(struct dma_fence_array *array,
> seqno);
> init_irq_work(&array->work, irq_dma_fence_array_work);
>
> +#if IS_ENABLED(CONFIG_PROVE_LOCKING)
> + lockdep_set_class(&array->base.inline_lock, &dma_fence_array_lock_key);
> +#endif
> +
> atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
> array->fences = fences;
>
> diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
> index a707792b6025..aa144b8c3534 100644
> --- a/drivers/dma-buf/dma-fence-chain.c
> +++ b/drivers/dma-buf/dma-fence-chain.c
> @@ -242,6 +242,9 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> struct dma_fence *fence,
> uint64_t seqno)
> {
> +#if IS_ENABLED(CONFIG_PROVE_LOCKING)
> + static struct lock_class_key dma_fence_chain_lock_key;
> +#endif
> struct dma_fence_chain *prev_chain = to_dma_fence_chain(prev);
> uint64_t context;
>
> @@ -263,6 +266,10 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> dma_fence_init64(&chain->base, &dma_fence_chain_ops, NULL,
> context, seqno);
>
> +#if IS_ENABLED(CONFIG_PROVE_LOCKING)
> + lockdep_set_class(&chain->base.inline_lock, &dma_fence_chain_lock_key);
> +#endif
> +
> /*
> * Chaining dma_fence_chain container together is only allowed through
> * the prev fence and not through the contained fence.
>
> Matt
>
> > Signed-off-by: Christian König <christian.koenig@amd.com>
> > ---
> > drivers/dma-buf/dma-fence-chain.c | 3 ++-
> > include/linux/dma-fence-chain.h | 1 +
> > 2 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
> > index a707792b6025..a8a90acf4f34 100644
> > --- a/drivers/dma-buf/dma-fence-chain.c
> > +++ b/drivers/dma-buf/dma-fence-chain.c
> > @@ -245,6 +245,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> > struct dma_fence_chain *prev_chain = to_dma_fence_chain(prev);
> > uint64_t context;
> >
> > + spin_lock_init(&chain->lock);
> > rcu_assign_pointer(chain->prev, prev);
> > chain->fence = fence;
> > chain->prev_seqno = 0;
> > @@ -260,7 +261,7 @@ void dma_fence_chain_init(struct dma_fence_chain *chain,
> > seqno = max(prev->seqno, seqno);
> > }
> >
> > - dma_fence_init64(&chain->base, &dma_fence_chain_ops, NULL,
> > + dma_fence_init64(&chain->base, &dma_fence_chain_ops, &chain->lock,
> > context, seqno);
> >
> > /*
> > diff --git a/include/linux/dma-fence-chain.h b/include/linux/dma-fence-chain.h
> > index df3beadf1515..5cd3ba53b4a1 100644
> > --- a/include/linux/dma-fence-chain.h
> > +++ b/include/linux/dma-fence-chain.h
> > @@ -46,6 +46,7 @@ struct dma_fence_chain {
> > */
> > struct irq_work work;
> > };
> > + spinlock_t lock;
> > };
> >
> >
> > --
> > 2.43.0
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-02-24 15:27 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2026-02-23 19:57 [PATCH] dma-buf: revert "use inline lock for the dma-fence-chain" Christian König
2026-02-23 20:18 ` Matthew Brost
2026-02-24 15:27 ` Matthew Brost
2026-02-23 20:45 ` ✗ i915.CI.BAT: failure for " Patchwork
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