Re: [PATCH 03/14] drm/i915/execlists: Flush the tasklet on parking

Tvrtko Ursulin
2019-05-02T13:48:20Z

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@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;
> }
>