[Intel-gfx] [PATCH 01/28] drm/i915: Adjust the sentinel assert to match implementation

[Tvrtko Ursulin]

666
On 08/06/2020 10:33, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2020-06-08 08:44:01)
>>
>> On 07/06/2020 23:20, Chris Wilson wrote:
>>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>>
>>> Sentinels are supposed to be last reqeusts in the elsp queue, not the
>>> only one, so adjust the assert accordingly.
>>>
>>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/gt/intel_lrc.c | 14 +++-----------
>>>    1 file changed, 3 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
>>> index d55a5e0466e5..db8a170b0e5c 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
>>> @@ -1635,9 +1635,9 @@ assert_pending_valid(const struct intel_engine_execlists *execlists,
>>>                ccid = ce->lrc.ccid;
>>>    
>>>                /*
>>> -              * Sentinels are supposed to be lonely so they flush the
>>> -              * current exection off the HW. Check that they are the
>>> -              * only request in the pending submission.
>>> +              * Sentinels are supposed to be the last request so they flush
>>> +              * the current exection off the HW. Check that they are the only
>>> +              * request in the pending submission.
>>>                 */
>>>                if (sentinel) {
>>>                        GEM_TRACE_ERR("%s: context:%llx after sentinel in pending[%zd]\n",
>>> @@ -1646,15 +1646,7 @@ assert_pending_valid(const struct intel_engine_execlists *execlists,
>>>                                      port - execlists->pending);
>>>                        return false;
>>>                }
>>> -
>>>                sentinel = i915_request_has_sentinel(rq);
>>
>> FWIW I was changing it to "sentinel |= ..." so it keeps working if we
>> decide to use more than 2 elsp ports on Icelake one day.
> 
> But it will always fail on the next port...

I don't follow. Sentinel has to be last so if it fails on the next port 
it is correct to do so, no?

Regards,

Tvrtko