[Intel-gfx] [PATCH] drm/i915: Tidy up GEM_TRACE around execlists

[Tvrtko Ursulin]

On 20/12/2017 09:06, Chris Wilson wrote:
> Looking at the coordination of resets with the submission of execlists,
> it will be useful to have a GEM_TRACE for when we issue the reset.
> Whilst there tidy up the other GEM_TRACE to always include the engine
> name, and be careful not to trust any pointers prior to asserts.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_lrc.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 6205d320b86f..84029806cf3f 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -504,7 +504,7 @@ static void inject_preempt_context(struct intel_engine_cs *engine)
>   	ce->ring->tail &= (ce->ring->size - 1);
>   	ce->lrc_reg_state[CTX_RING_TAIL+1] = ce->ring->tail;
>   
> -	GEM_TRACE("\n");
> +	GEM_TRACE("%s\n", engine->name);
>   	for (n = execlists_num_ports(&engine->execlists); --n; )
>   		elsp_write(0, engine->execlists.elsp);
>   
> @@ -906,7 +906,7 @@ static void execlists_submission_tasklet(unsigned long data)
>   			GEM_TRACE("%s out[0]: ctx=%d.%d, seqno=%x\n",
>   				  engine->name,
>   				  port->context_id, count,
> -				  rq->global_seqno);
> +				  rq ? rq->global_seqno : 0);

rq can be NULL here? What's with the --count below then, wouldn't it 
underflow since I assume rq == NULL means count == 0 as well?

>   			GEM_BUG_ON(count == 0);
>   			if (--count == 0) {
>   				GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED);
> @@ -1555,6 +1555,8 @@ static void reset_common_ring(struct intel_engine_cs *engine,
>   	struct intel_context *ce;
>   	unsigned long flags;
>   
> +	GEM_TRACE("%s: seqno=%x\n",
> +		  engine->name, request ? request->global_seqno : 0);

This one is legit.

>   	spin_lock_irqsave(&engine->timeline->lock, flags);
>   
>   	/*
> 

Regards,

Tvrtko