On 10/11/2024 5:16 PM, Matthew Auld wrote:
> On 11/10/2024 15:10, Nirmoy Das wrote:
>>
>> On 10/11/2024 3:25 PM, Nirmoy Das wrote:
>>> do_comapre() can return success after wait_woken() which is treated as
>>> -ETIME here.
>>
>> s/after wait_woken()/after timedout wait_woken()
>>
>> I will resend with that change.
>>
>>>
>>> Fixes: e670f0b4ef24 ("drm/xe/uapi: Return correct error code for xe_wait_user_fence_ioctl")
>>> Cc: <stable@xxxxxxxxxxxxxxx> # v6.8+
>>> Cc: Bommu Krishnaiah <krishnaiah.bommu@xxxxxxxxx>
>>> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1630
>>> Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
>>> Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
>>> Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
>>> ---
>>> drivers/gpu/drm/xe/xe_wait_user_fence.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/xe/xe_wait_user_fence.c b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>>> index d46fa8374980..d532283d4aa3 100644
>>> --- a/drivers/gpu/drm/xe/xe_wait_user_fence.c
>>> +++ b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>>> @@ -169,7 +169,7 @@ int xe_wait_user_fence_ioctl(struct drm_device *dev, void *data,
>>> args->timeout = 0;
>>> }
>>> - if (!timeout && !(err < 0))
>
> Since err > 0 is impossible, this could be written as: && err == 0.
>
> So I think this is saying: if we have timedout and err does not already have an error set then go ahead and set to -ETIME since we hit the timeout.
This is the issue here. This assumption is wrong that if timeout happen then return -ETIME even though the fence is signaled.
> But it might have -EIO or -ERESTARTSYS for example, which should then take precedence over -ETIME...
>
>>> + if (!timeout && err < 0)
>
> ...this would then trample the existing err. The err can either be zero or an existing error at this point, so I think just remove this entire check:
>
> - if (!timeout && !(err < 0))
> - err = -ETIME;
> -
>
> ?
Yes, this works for me. The for loops sets err correctly even when there is real timeout on not-signaled fence.
I will resend a v2.
Regards,
Nirmoy
>
>>> err = -ETIME;
>>> if (q)
