[PATCH] drm/i915/display: Change ret value type from int to long

Jani Nikula jani.nikula at linux.intel.com
Fri Jul 4 12:50:49 UTC 2025


On Fri, 04 Jul 2025, Christian König <christian.koenig at amd.com> wrote:
> On 04.07.25 14:00, Jani Nikula wrote:
>> On Fri, 04 Jul 2025, Aakash Deep Sarkar <aakash.deep.sarkar at intel.com> wrote:
>>> dma_fence_wait_timeout returns a long type but the driver is
>>> only using the lower 32 bits of the retval and discarding the
>>> upper 32 bits.
>>>
>>> This is particularly problematic if there are already signalled
>>> or stub fences on some of the hw planes. In this case the
>>> dma_fence_wait_timeout function will immediately return with
>>> timeout value MAX_SCHEDULE_TIMEOUT (0x7fffffffffffffff) since
>>> the fence is already signalled.
>
> That is not correct. If the fence is signaled dma_fence_wait_timeout()
> returns the remaining timeout or at least 1 if the input timeout was
> 0.
>
> Could be that i915 has a separately implemented fence_ops->wait
> callback which incorrectly returns MAX_SCHEDULE_TIMEOUT, but i
> strongly doubt that because that would break tons of stuff.

Thanks, good thing I Cc'd folks. :)

BR,
Jani.


-- 
Jani Nikula, Intel


More information about the Intel-gfx mailing list