Commit 4856254d authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Repeat wait_for_idle for retirement workers 



Since we may retire timelines from secondary workers,
intel_gt_retire_requests() is not always a reliable indicator that all
pending retirements are complete. If we do detect secondary workers are
in progress, recommend intel_gt_wait_for_idle() to repeat the retirement
check.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Acked-by: default avatarAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221180204.1201217-1-chris@chris-wilson.co.uk
parent e6ba7648

drivers/gpu/drm/i915/gt/intel_engine.h

+1 −1
Original line number Diff line number Diff line
@@ -282,7 +282,7 @@ static inline void __intel_engine_reset(struct intel_engine_cs *engine, 


bool intel_engines_are_idle(struct intel_gt *gt);

bool intel_engine_is_idle(struct intel_engine_cs *engine);

void intel_engine_flush_submission(struct intel_engine_cs *engine);

bool intel_engine_flush_submission(struct intel_engine_cs *engine);



void intel_engines_reset_default_submission(struct intel_gt *gt);

drivers/gpu/drm/i915/gt/intel_engine_cs.c

+5 −1
Original line number Diff line number Diff line
@@ -1079,9 +1079,10 @@ static bool ring_is_idle(struct intel_engine_cs *engine) 
	return idle;

}



void intel_engine_flush_submission(struct intel_engine_cs *engine)

bool intel_engine_flush_submission(struct intel_engine_cs *engine)

{

	struct tasklet_struct *t = &engine->execlists.tasklet;

	bool active = tasklet_is_locked(t);



	if (__tasklet_is_scheduled(t)) {

		local_bh_disable();
@@ -1092,10 +1093,13 @@ void intel_engine_flush_submission(struct intel_engine_cs *engine) 
			tasklet_unlock(t);

		}

		local_bh_enable();

		active = true;

	}



	/* Otherwise flush the tasklet if it was running on another cpu */

	tasklet_unlock_wait(t);



	return active;

}



/**

drivers/gpu/drm/i915/gt/intel_gt_requests.c

+14 −9
Original line number Diff line number Diff line
@@ -23,15 +23,18 @@ static void retire_requests(struct intel_timeline *tl) 
			break;

}



static void flush_submission(struct intel_gt *gt)

static bool flush_submission(struct intel_gt *gt)

{

	struct intel_engine_cs *engine;

	enum intel_engine_id id;

	bool active = false;



	for_each_engine(engine, gt, id) {

		intel_engine_flush_submission(engine);

		flush_work(&engine->retire_work);

		active |= intel_engine_flush_submission(engine);

		active |= flush_work(&engine->retire_work);

	}



	return active;

}



static void engine_retire(struct work_struct *work)
@@ -120,9 +123,10 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout) 


	spin_lock(&timelines->lock);

	list_for_each_entry_safe(tl, tn, &timelines->active_list, link) {

		if (!mutex_trylock(&tl->mutex)) {

			active_count++; /* report busy to caller, try again? */

		if (!mutex_trylock(&tl->mutex))

			continue;

		}



		intel_timeline_get(tl);

		GEM_BUG_ON(!atomic_read(&tl->active_count));
@@ -147,10 +151,10 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout) 


		/* Resume iteration after dropping lock */

		list_safe_reset_next(tl, tn, link);

		if (atomic_dec_and_test(&tl->active_count)) {

		if (atomic_dec_and_test(&tl->active_count))

			list_del(&tl->link);

			active_count--;

		}

		else

			active_count += i915_active_fence_isset(&tl->last_request);



		mutex_unlock(&tl->mutex);
@@ -165,7 +169,8 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout) 
	list_for_each_entry_safe(tl, tn, &free, link)

		__intel_timeline_free(&tl->kref);



	flush_submission(gt);

	if (flush_submission(gt))

		active_count++;



	return active_count ? timeout : 0;

}

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