diff mbox

[v2] drm/i915/guc: Keep guc submission permanently engaged

Message ID 20180517200610.2332-1-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Wilson May 17, 2018, 8:06 p.m. UTC 
We make a decision at module load whether to use the GuC backend or not,
but lose that setup across set-wedge. Currently, the guc doesn't
override the engine->set_default_submission hook letting execlists sneak
back in temporarily on unwedging leading to an unbalanced park/unpark.

v2: Remove comment about switching back temporarily to execlists on
guc_submission_disable(). We currently only call disable on shutdown,
and plan to also call disable before suspend and reset, in which case we
will either restore guc submission or mark the driver as wedged, making
the reset back to execlists pointless.

Testcase: igt/gem_eio
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/i915/intel_guc_submission.c | 37 ++++++++++++++-------
 drivers/gpu/drm/i915/intel_lrc.c            |  2 +-
 drivers/gpu/drm/i915/intel_lrc.h            |  2 ++
 3 files changed, 28 insertions(+), 13 deletions(-)

Comments

Chris Wilson May 17, 2018, 10:28 p.m. UTC | #1 
Quoting Chris Wilson (2018-05-17 21:06:10)
> We make a decision at module load whether to use the GuC backend or not,
> but lose that setup across set-wedge. Currently, the guc doesn't
> override the engine->set_default_submission hook letting execlists sneak
> back in temporarily on unwedging leading to an unbalanced park/unpark.
> 
> v2: Remove comment about switching back temporarily to execlists on
> guc_submission_disable(). We currently only call disable on shutdown,
> and plan to also call disable before suspend and reset, in which case we
> will either restore guc submission or mark the driver as wedged, making
> the reset back to execlists pointless.
> 
> Testcase: igt/gem_eio
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>

I think this makes sense given the current limitations; and fixes the
crash we have in gem_eio on guc. Worth pulling into your series Michal
and giving it another spin?
-Chris
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 637e852888ec..fdd4cfcc0e8e 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -1264,6 +1264,29 @@  static void guc_submission_unpark(struct intel_engine_cs *engine)
 	intel_engine_pin_breadcrumbs_irq(engine);
 }
 
+static void guc_set_default_submission(struct intel_engine_cs *engine)
+{
+	/*
+	 * We inherit a bunch of functions from execlists that we'd like
+	 * to keep using:
+	 *
+	 *    engine->submit_request = execlists_submit_request;
+	 *    engine->cancel_requests = execlists_cancel_requests;
+	 *    engine->schedule = execlists_schedule;
+	 *
+	 * But we need to override the actual submission backend in order
+	 * to talk to the GuC.
+	 */
+	execlists_set_default_submission(engine);
+
+	engine->execlists.tasklet.func = guc_submission_tasklet;
+
+	engine->park = guc_submission_park;
+	engine->unpark = guc_submission_unpark;
+
+	engine->flags &= ~I915_ENGINE_SUPPORTS_STATS;
+}
+
 int intel_guc_submission_enable(struct intel_guc *guc)
 {
 	struct drm_i915_private *dev_priv = guc_to_i915(guc);
@@ -1302,17 +1325,10 @@  int intel_guc_submission_enable(struct intel_guc *guc)
 	guc_interrupts_capture(dev_priv);
 
 	for_each_engine(engine, dev_priv, id) {
-		struct intel_engine_execlists * const execlists =
-			&engine->execlists;
-
-		execlists->tasklet.func = guc_submission_tasklet;
-
 		engine->reset.prepare = guc_reset_prepare;
+		engine->set_default_submission = guc_set_default_submission;
 
-		engine->park = guc_submission_park;
-		engine->unpark = guc_submission_unpark;
-
-		engine->flags &= ~I915_ENGINE_SUPPORTS_STATS;
+		engine->set_default_submission(engine);
 	}
 
 	return 0;
@@ -1326,9 +1342,6 @@  void intel_guc_submission_disable(struct intel_guc *guc)
 
 	guc_interrupts_release(dev_priv);
 	guc_clients_doorbell_fini(guc);
-
-	/* Revert back to manual ELSP submission */
-	intel_engines_reset_default_submission(dev_priv);
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index d6e698d3f858..758126b5a448 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2289,7 +2289,7 @@  void intel_logical_ring_cleanup(struct intel_engine_cs *engine)
 	kfree(engine);
 }
 
-static void execlists_set_default_submission(struct intel_engine_cs *engine)
+void execlists_set_default_submission(struct intel_engine_cs *engine)
 {
 	engine->submit_request = execlists_submit_request;
 	engine->cancel_requests = execlists_cancel_requests;
diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index 4ec7d8dd13c8..e64f47e612f4 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -111,4 +111,6 @@  intel_lr_context_descriptor(struct i915_gem_context *ctx,
 	return to_intel_context(ctx, engine)->lrc_desc;
 }
 
+void execlists_set_default_submission(struct intel_engine_cs *engine);
+
 #endif /* _INTEL_LRC_H_ */