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From 596f087757710426f4a33b1f7d717d574abfd561 Mon Sep 17 00:00:00 2001
From: Matthew Brost <matthew.brost@intel.com>
Date: Thu, 9 Sep 2021 09:47:25 -0700
Subject: drm/i915/guc: Don't drop ce->guc_active.lock when unwinding context
Git-commit: 88209a8ecb8b8752322908a3c3362a001bdc3a39
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

Don't drop ce->guc_active.lock when unwinding a context after reset.
At one point we had to drop this because of a lock inversion but that is
no longer the case. It is much safer to hold the lock so let's do that.

Fixes: eb5e7da736f3 ("drm/i915/guc: Reset implementation for new GuC interface")
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-5-matthew.brost@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 4 ----
 1 file changed, 4 deletions(-)

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 0c1e6b465fba..31bbfe5479ae 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -813,8 +813,6 @@ __unwind_incomplete_requests(struct intel_context *ce)
 			continue;
 
 		list_del_init(&rq->sched.link);
-		spin_unlock(&ce->guc_active.lock);
-
 		__i915_request_unsubmit(rq);
 
 		/* Push the request back into the queue for later resubmission. */
@@ -827,8 +825,6 @@ __unwind_incomplete_requests(struct intel_context *ce)
 
 		list_add(&rq->sched.link, pl);
 		set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
-
-		spin_lock(&ce->guc_active.lock);
 	}
 	spin_unlock(&ce->guc_active.lock);
 	spin_unlock_irqrestore(&sched_engine->lock, flags);
-- 
2.38.1