[PATCH 5/9] drm/i915/guc: Flush the work queue for GuC generated G2H

[Matthew Brost]

Flush the work queue for GuC generated G2H messages durinr a GT reset.
This is accomplished by spinning on the the list of outstanding G2H to
go empty.

Fixes: eb5e7da736f3 ("drm/i915/guc: Reset implementation for new GuC interface")
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Cc: <stable at vger.kernel.org>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 3cd2da6f5c03..e5eb2df11b4a 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -727,6 +727,11 @@ void intel_guc_submission_reset_prepare(struct intel_guc *guc)
 			wait_for_reset(guc, &guc->outstanding_submission_g2h);
 		} while (!list_empty(&guc->ct.requests.incoming));
 	}
+
+	/* Flush any GuC generated G2H */
+	while (!list_empty(&guc->ct.requests.incoming))
+		msleep(20);
+
 	scrub_guc_desc_for_outstanding_g2h(guc);
 }
 
-- 
2.32.0