[Intel-gfx] [PATCH] drm/i915/guc: Check that the breadcrumb irq is enabled

[Chris Wilson]

Our execlists emulation for GuC requires use of the breadcrumb following
every request as a simulcrum for the context-switch interrupt, which we
then use to drive the submission tasklet. Therefore, when we unpark the
engine for use with the GuC, we pin the breadcrumb interrupt to keep it
enabled for the duration. This has to be remain so across all resets,
wedging and resume, so check we do have the irq enabled when we start
submitting requests to the GuC and on all submissions thereafter.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_submission.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 97121230656c..a7957b669b68 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -758,6 +758,8 @@ static void guc_submission_tasklet(unsigned long data)
 	struct execlist_port *port = execlists->port;
 	struct i915_request *rq;
 
+	GEM_BUG_ON(!READ_ONCE(engine->breadcrumbs.irq_enabled));
+
 	rq = port_request(port);
 	while (rq && i915_request_completed(rq)) {
 		trace_i915_request_out(rq);
-- 
2.17.0