[Intel-gfx] [PATCH 2/4] drm/i915: Only trigger missed-seqno checking next to boundary

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> If we have more interrupts pending (because we know there are more
> breadcrumb signals before the completion), then we do not need to
> trigger an irq_seqno_barrier or even wakeup the task on this interrupt
> as there will be another. To allow some margin of error (we are trying
> to work around incoherent seqno after all), we wakeup the breadcrumb
> before the target as well as on the target.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>

Thanks for splitting this out.

Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_irq.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 56a080bc4498..55aba89adfb1 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1182,7 +1182,8 @@ static void notify_ring(struct intel_engine_cs *engine)
>  
>  			tsk = wait->tsk;
>  		} else {
> -			if (engine->irq_seqno_barrier) {
> +			if (engine->irq_seqno_barrier &&
> +			    i915_seqno_passed(seqno, wait->seqno - 1)) {
>  				set_bit(ENGINE_IRQ_BREADCRUMB,
>  					&engine->irq_posted);
>  				tsk = wait->tsk;
> -- 
> 2.18.0