[Intel-gfx] [PATCH 6/7] drm/i915: Convert execlists_ctx_descriptor() for requests

[Dave Gordon]

On 08/07/15 17:40, Yu Dai wrote:
> On 07/03/2015 07:09 AM, Mika Kuoppala wrote:
>> Pass around requests to carry context deeper in callchain.
>>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_lrc.c | 14 ++++++--------
>>   1 file changed, 6 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_lrc.c
>> b/drivers/gpu/drm/i915/intel_lrc.c
>> index c3c029a..67ff460 100644
>> --- a/drivers/gpu/drm/i915/intel_lrc.c
>> +++ b/drivers/gpu/drm/i915/intel_lrc.c
>> @@ -261,10 +261,11 @@ u32 intel_execlists_ctx_id(struct
>> drm_i915_gem_object *ctx_obj)
>>       return lrca >> 12;
>>   }
>> -static uint64_t execlists_ctx_descriptor(struct intel_engine_cs *ring,
>> -                     struct drm_i915_gem_object *ctx_obj)
>> +static uint64_t execlists_ctx_descriptor(struct drm_i915_gem_request
>> *rq)
>>   {
>
> GuC patch series tries to utilize this function. However, changing from
> ring/context to request makes it unusable in the case where request is
> not needed (not available). This context descriptor has nothing to do
> with drm_i915_gem_request IMO. And it is waste of time to call it for
> each batch submission. This value is fixed when context is pinned. Maybe
> add a member ctx_desc into intel_context->engine; initialize the value
> within intel_lr_context_pin; then use it whenever needed.
>
> Thanks,
> Alex

Yes, I've effectively reversed this in the next GuC submission series, 
since we don't have a request during setup, and this function doesn't 
actually need one either; it's only being used as a handle for 
extracting the context and ring.

So in my version it will take an intel_context and a ring so it's up to 
the caller to extract those from the drm_i915_gem_request (rq->ctx) and 
(rq->ring) and pass them separately. Then the GuC can use it during 
setup as well as at runtime :)

.Dave.