[PATCH] drm/xe/ufence: Flush xe ordered_wq in case of ufence timeout

[Nirmoy Das]

On 10/24/2024 4:05 AM, Ghimiray, Himal Prasad wrote:
>
>
> On 23-10-2024 21:28, Nirmoy Das wrote:
>> Flush xe ordered_wq in case of ufence timeout which is observed
>> on LNL and that points recent scheduling issue with E-cores.
>>
>> This is similar to the recent fix:
>> commit e51527233804 ("drm/xe/guc/ct: Flush g2h worker in case of g2h
>> response timeout") and should be removed once there is E core
>> scheduling fix.
>>
>> Cc: Badal Nilawar <badal.nilawar at intel.com>
>> Cc: Matthew Auld <matthew.auld at intel.com>
>> Cc: John Harrison <John.C.Harrison at Intel.com>
>> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
>> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2754
>
> Same comment as "drm/xe/guc/tlb: Flush g2h worker in case of tlb timeout."


AFAIS recent failures are all on LNL. I had another fix  https://patchwork.freedesktop.org/patch/msgid/20241011151029.4160630-1-nirmoy.das@intel.com   

which should fixe timeout issue for all platforms but LNL is unique here.


Regards,

Nirmoy

>
> BR
> Himal
>
>> Suggested-by: Matthew Brost <matthew.brost at intel.com>
>> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_wait_user_fence.c | 11 +++++++++++
>>   1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_wait_user_fence.c b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> index f5deb81eba01..7f034871345b 100644
>> --- a/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> +++ b/drivers/gpu/drm/xe/xe_wait_user_fence.c
>> @@ -155,6 +155,17 @@ int xe_wait_user_fence_ioctl(struct drm_device *dev, void *data,
>>           }
>>             if (!timeout) {
>> +            /*
>> +             * This is analogous to e51527233804 ("drm/xe/guc/ct: Flush g2h worker
>> +             * in case of g2h response timeout")
>> +             *
>> +             * TODO: Drop this change once workqueue scheduling delay issue is
>> +             * fixed on LNL Hybrid CPU.
>> +             */
>> +            __flush_workqueue(xe->ordered_wq);
>> +            err = do_compare(addr, args->value, args->mask, args->op);
>> +            if (err <= 0)
>> +                break;
>>               err = -ETIME;
>>               break;
>>           }
>