[PATCH] dma-fence: use correct callback in dma_fence_timeline_name()

[PATCH] dma-fence: use correct callback in dma_fence_timeline_name()

[André Draszik]

dma_fence_timeline_name() is a wrapper around
dma_fence_ops::get_timeline_name(). Since the blamed commit below, it
calls an incorrect callback.

Update it to restore functionality by calling the intended callback.

Fixes: 62918542b7bf ("dma-fence: Fix sparse warnings due __rcu annotations")
Signed-off-by: André Draszik <andre.draszik@linaro.org>
---
 drivers/dma-buf/dma-fence.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index b3bfa6943a8e..5292d714419b 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -1202,7 +1202,7 @@ const char __rcu *dma_fence_timeline_name(struct dma_fence *fence)
 	/* RCU protection is required for safe access to returned string */
 	ops = rcu_dereference(fence->ops);
 	if (!dma_fence_test_signaled_flag(fence))
-		return (const char __rcu *)ops->get_driver_name(fence);
+		return (const char __rcu *)ops->get_timeline_name(fence);
 	else
 		return (const char __rcu *)"signaled-timeline";
 }

---
base-commit: e2cae00c05d196491c318196792297f2dfbaa02c
change-id: 20260618-linux-drm_crtc_fix-267655a1c89f

Best regards,
-- 
André Draszik <andre.draszik@linaro.org>

Re: [PATCH] dma-fence: use correct callback in dma_fence_timeline_name()

[Christian König]

On 6/18/26 14:00, André Draszik wrote:
> dma_fence_timeline_name() is a wrapper around
> dma_fence_ops::get_timeline_name(). Since the blamed commit below, it
> calls an incorrect callback.
> 
> Update it to restore functionality by calling the intended callback.
> 
> Fixes: 62918542b7bf ("dma-fence: Fix sparse warnings due __rcu annotations")
> Signed-off-by: André Draszik <andre.draszik@linaro.org>

I'm like 99% sure we had that already fixed weeks ago, but somehow it looks like that was never merged to drm-misc-fixes.

Anyway Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>  drivers/dma-buf/dma-fence.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index b3bfa6943a8e..5292d714419b 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -1202,7 +1202,7 @@ const char __rcu *dma_fence_timeline_name(struct dma_fence *fence)
>         /* RCU protection is required for safe access to returned string */
>         ops = rcu_dereference(fence->ops);
>         if (!dma_fence_test_signaled_flag(fence))
> -               return (const char __rcu *)ops->get_driver_name(fence);
> +               return (const char __rcu *)ops->get_timeline_name(fence);
>         else
>                 return (const char __rcu *)"signaled-timeline";
>  }
> 
> ---
> base-commit: e2cae00c05d196491c318196792297f2dfbaa02c
> change-id: 20260618-linux-drm_crtc_fix-267655a1c89f
> 
> Best regards,
> --
> André Draszik <andre.draszik@linaro.org>
> 

Re: [PATCH] dma-fence: use correct callback in dma_fence_timeline_name()

[Tvrtko Ursulin]

On 18/06/2026 14:46, Christian König wrote:
> On 6/18/26 14:00, André Draszik wrote:
>> dma_fence_timeline_name() is a wrapper around
>> dma_fence_ops::get_timeline_name(). Since the blamed commit below, it
>> calls an incorrect callback.
>>
>> Update it to restore functionality by calling the intended callback.
>>
>> Fixes: 62918542b7bf ("dma-fence: Fix sparse warnings due __rcu annotations")
>> Signed-off-by: André Draszik <andre.draszik@linaro.org>
> I'm like 99% sure we had that already fixed weeks ago, but somehow it looks like that was never merged to drm-misc-fixes.
>
> Anyway Reviewed-by: Christian König <christian.koenig@amd.com>

I was also perplexed and took me some digging to realise what had happened.

The copy-and-paste bug was indeed originally fixed in:

commit 033559473dd3b55558b535aa37b8848c207b5cbb
Author:     Akash Goel <akash.goel@arm.com>
AuthorDate: Tue Oct 21 17:09:51 2025 +0100
Commit:     Tvrtko Ursulin <tursulin@ursulin.net>
CommitDate: Fri Oct 24 16:56:37 2025 +0100

     dma-fence: Fix safe access wrapper to call timeline name method


But waaay before that I sent a fix for something else which touched 
those lines not noticing the copy-and-paste, fixing a different issue. 
That one however was not merged until earlier this year:

commit 62918542b7bf08860a60ebbde7654486e0ac0776
Author:     Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
AuthorDate: Mon Jun 16 16:59:52 2025 +0100
Commit:     Christian König <christian.koenig@amd.com>
CommitDate: Mon Feb 9 14:05:20 2026 +0100

     dma-fence: Fix sparse warnings due __rcu annotations

Notice the authored vs commited dates.

I guess it was a silent conflict which overwrote the earlier fix and 
restore the copy-and-paste bug.

Regards,

Tvrtko

>
>> ---
>>   drivers/dma-buf/dma-fence.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
>> index b3bfa6943a8e..5292d714419b 100644
>> --- a/drivers/dma-buf/dma-fence.c
>> +++ b/drivers/dma-buf/dma-fence.c
>> @@ -1202,7 +1202,7 @@ const char __rcu *dma_fence_timeline_name(struct dma_fence *fence)
>>          /* RCU protection is required for safe access to returned string */
>>          ops = rcu_dereference(fence->ops);
>>          if (!dma_fence_test_signaled_flag(fence))
>> -               return (const char __rcu *)ops->get_driver_name(fence);
>> +               return (const char __rcu *)ops->get_timeline_name(fence);
>>          else
>>                  return (const char __rcu *)"signaled-timeline";
>>   }
>>
>> ---
>> base-commit: e2cae00c05d196491c318196792297f2dfbaa02c
>> change-id: 20260618-linux-drm_crtc_fix-267655a1c89f
>>
>> Best regards,
>> --
>> André Draszik <andre.draszik@linaro.org>
>>

Re: [PATCH] dma-fence: use correct callback in dma_fence_timeline_name()

[pstanner]

On Thu, 2026-06-18 at 20:30 +0200, Tvrtko Ursulin wrote:
> 
> On 18/06/2026 14:46, Christian König wrote:
> > On 6/18/26 14:00, André Draszik wrote:
> > > dma_fence_timeline_name() is a wrapper around
> > > dma_fence_ops::get_timeline_name(). Since the blamed commit below, it
> > > calls an incorrect callback.
> > > 
> > > Update it to restore functionality by calling the intended callback.
> > > 
> > > Fixes: 62918542b7bf ("dma-fence: Fix sparse warnings due __rcu annotations")
> > > Signed-off-by: André Draszik <andre.draszik@linaro.org>

Reviewed-by: Philipp Stanner <phasta@kernel.org>

> > I'm like 99% sure we had that already fixed weeks ago, but somehow it looks like that was never merged to drm-misc-fixes.

I'm also very sure that we had shot that bug down not too long in the
past.

> > 
> > Anyway Reviewed-by: Christian König <christian.koenig@amd.com>
> 
> I was also perplexed and took me some digging to realise what had happened.
> 
> The copy-and-paste bug was indeed originally fixed in:
> 
> commit 033559473dd3b55558b535aa37b8848c207b5cbb
> Author:     Akash Goel <akash.goel@arm.com>
> AuthorDate: Tue Oct 21 17:09:51 2025 +0100
> Commit:     Tvrtko Ursulin <tursulin@ursulin.net>
> CommitDate: Fri Oct 24 16:56:37 2025 +0100
> 
>      dma-fence: Fix safe access wrapper to call timeline name method
> 
> 
> But waaay before that I sent a fix for something else which touched 
> those lines not noticing the copy-and-paste, fixing a different issue. 
> That one however was not merged until earlier this year:
> 
> commit 62918542b7bf08860a60ebbde7654486e0ac0776
> Author:     Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
> AuthorDate: Mon Jun 16 16:59:52 2025 +0100
> Commit:     Christian König <christian.koenig@amd.com>
> CommitDate: Mon Feb 9 14:05:20 2026 +0100
> 
>      dma-fence: Fix sparse warnings due __rcu annotations
> 
> Notice the authored vs commited dates.
> 
> I guess it was a silent conflict which overwrote the earlier fix and 
> restore the copy-and-paste bug.

silent conflict? If that can happen with our git workflow, how is it
that we don't see things like that more often?


P.