From 9e76b8434e52fdbcaea612ede544094044b6aafd Mon Sep 17 00:00:00 2001
From: Matthew Brost <matthew.brost@intel.com>
Date: Thu, 9 Sep 2021 09:47:33 -0700
Subject: drm/i915/guc: Take context ref when cancelling request
Git-commit: 422cda4f50091bdfa114c7d19fce31919c920fe1
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

A context can get destroyed after cancelling a request, if a context or
GT reset occurs, so take a reference to context when cancelling a
request.

Fixes: 62eaf0ae217d ("drm/i915/guc: Support request cancellation")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-13-matthew.brost@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

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 5970c54a2e72..e036a171ff17 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1624,8 +1624,10 @@ static void guc_context_cancel_request(struct intel_context *ce,
 				       struct i915_request *rq)
 {
 	if (i915_sw_fence_signaled(&rq->submit)) {
-		struct i915_sw_fence *fence = guc_context_block(ce);
+		struct i915_sw_fence *fence;
 
+		intel_context_get(ce);
+		fence = guc_context_block(ce);
 		i915_sw_fence_wait(fence);
 		if (!i915_request_completed(rq)) {
 			__i915_request_skip(rq);
@@ -1640,6 +1642,7 @@ static void guc_context_cancel_request(struct intel_context *ce,
 		flush_work(&ce_to_guc(ce)->ct.requests.worker);
 
 		guc_context_unblock(ce);
+		intel_context_put(ce);
 	}
 }
 
-- 
2.38.1