From dd41826a0f1e563805e924ac90b0b4f45d09e4e2 Mon Sep 17 00:00:00 2001
From: Matthew Brost <matthew.brost@intel.com>
Date: Thu, 28 Oct 2021 15:42:24 -0700
Subject: drm/i915/resets: Don't set / test for per-engine reset bits with GuC
 submission
Git-commit: 03f060b73f9ad9555f6251cac21c692df8112a68
Patch-mainline: v5.17-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 set, test for, or clear per-engine reset bits with GuC submission
as the GuC owns the per engine resets not the i915. Setting, testing
for, and clearing these bits is causing issues with the hangcheck
selftest. Rather than change to test to not use these bits, rip the use
of these bits out from the reset code.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211028224224.32693-1-matthew.brost@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gt/intel_reset.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index 91200c43951f..51b56b8e5003 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -1367,20 +1367,27 @@ void intel_gt_handle_error(struct intel_gt *gt,
 	/* Make sure i915_reset_trylock() sees the I915_RESET_BACKOFF */
 	synchronize_rcu_expedited();
 
-	/* Prevent any other reset-engine attempt. */
-	for_each_engine(engine, gt, tmp) {
-		while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
-					&gt->reset.flags))
-			wait_on_bit(&gt->reset.flags,
-				    I915_RESET_ENGINE + engine->id,
-				    TASK_UNINTERRUPTIBLE);
+	/*
+	 * Prevent any other reset-engine attempt. We don't do this for GuC
+	 * submission the GuC owns the per-engine reset, not the i915.
+	 */
+	if (!intel_uc_uses_guc_submission(&gt->uc)) {
+		for_each_engine(engine, gt, tmp) {
+			while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
+						&gt->reset.flags))
+				wait_on_bit(&gt->reset.flags,
+					    I915_RESET_ENGINE + engine->id,
+					    TASK_UNINTERRUPTIBLE);
+		}
 	}
 
 	intel_gt_reset_global(gt, engine_mask, msg);
 
-	for_each_engine(engine, gt, tmp)
-		clear_bit_unlock(I915_RESET_ENGINE + engine->id,
-				 &gt->reset.flags);
+	if (!intel_uc_uses_guc_submission(&gt->uc)) {
+		for_each_engine(engine, gt, tmp)
+			clear_bit_unlock(I915_RESET_ENGINE + engine->id,
+					 &gt->reset.flags);
+	}
 	clear_bit_unlock(I915_RESET_BACKOFF, &gt->reset.flags);
 	smp_mb__after_atomic();
 	wake_up_all(&gt->reset.queue);
-- 
2.38.1