[Intel-gfx] [PATCH 03/14] drm/i915/execlists: Flush the tasklet on parking

[Tvrtko Ursulin]

On 01/05/2019 12:45, Chris Wilson wrote:
> Tidy up the cleanup sequence by always ensure that the tasklet is
> flushed on parking (before we cleanup). The parking provides a
> convenient point to ensure that the backend is truly idle.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/gt/intel_lrc.c         | 7 ++++++-
>   drivers/gpu/drm/i915/intel_guc_submission.c | 1 +
>   2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 851e62ddcb87..7be54b868d8e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -2331,6 +2331,11 @@ static int gen8_init_rcs_context(struct i915_request *rq)
>   	return i915_gem_render_state_emit(rq);
>   }
>   
> +static void execlists_park(struct intel_engine_cs *engine)
> +{
> +	tasklet_kill(&engine->execlists.tasklet);

Isn't it actually a problem if tasklet is scheduled and unstarted, or 
even in progress at the point of engine getting parked?

Regards,

Tvrtko

> +}
> +
>   void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
>   {
>   	engine->submit_request = execlists_submit_request;
> @@ -2342,7 +2347,7 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
>   	engine->reset.reset = execlists_reset;
>   	engine->reset.finish = execlists_reset_finish;
>   
> -	engine->park = NULL;
> +	engine->park = execlists_park;
>   	engine->unpark = NULL;
>   
>   	engine->flags |= I915_ENGINE_SUPPORTS_STATS;
> diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
> index 4c814344809c..ed94001028f2 100644
> --- a/drivers/gpu/drm/i915/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/intel_guc_submission.c
> @@ -1363,6 +1363,7 @@ static void guc_interrupts_release(struct drm_i915_private *dev_priv)
>   
>   static void guc_submission_park(struct intel_engine_cs *engine)
>   {
> +	tasklet_kill(&engine->execlists.tasklet);
>   	intel_engine_unpin_breadcrumbs_irq(engine);
>   	engine->flags &= ~I915_ENGINE_NEEDS_BREADCRUMB_TASKLET;
>   }
>