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From f33ae5a8adcf70ae53873924fa18706b587ab029 Mon Sep 17 00:00:00 2001
From: John Harrison <John.C.Harrison@Intel.com>
Date: Mon, 26 Jul 2021 17:23:31 -0700
Subject: drm/i915/guc: Don't complain about reset races
Git-commit: d75dc57fee98294944f14069fd686b451754627d
Patch-mainline: v5.15-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

It is impossible to seal all race conditions of resets occurring
concurrent to other operations. At least, not without introducing
excesive mutex locking. Instead, don't complain if it occurs. In
particular, don't complain if trying to send a H2G during a reset.
Whatever the H2G was about should get redone once the reset is over.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-17-matthew.brost@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 5 ++++-
 drivers/gpu/drm/i915/gt/uc/intel_uc.c     | 4 ++++
 drivers/gpu/drm/i915/gt/uc/intel_uc.h     | 2 ++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
index 18917b443f05..22b4733b55e2 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -760,7 +760,10 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len,
 	int ret;
 
 	if (unlikely(!ct->enabled)) {
-		WARN(1, "Unexpected send: action=%#x\n", *action);
+		struct intel_guc *guc = ct_to_guc(ct);
+		struct intel_uc *uc = container_of(guc, struct intel_uc, guc);
+
+		WARN(!uc->reset_in_progress, "Unexpected send: action=%#x\n", *action);
 		return -ENODEV;
 	}
 
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
index e07c989968f9..77c1fe2ed883 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
@@ -550,6 +550,8 @@ void intel_uc_reset_prepare(struct intel_uc *uc)
 {
 	struct intel_guc *guc = &uc->guc;
 
+	uc->reset_in_progress = true;
+
 	/* Nothing to do if GuC isn't supported */
 	if (!intel_uc_supports_guc(uc))
 		return;
@@ -578,6 +580,8 @@ void intel_uc_reset_finish(struct intel_uc *uc)
 {
 	struct intel_guc *guc = &uc->guc;
 
+	uc->reset_in_progress = false;
+
 	/* Firmware expected to be running when this function is called */
 	if (intel_guc_is_fw_running(guc) && intel_uc_uses_guc_submission(uc))
 		intel_guc_submission_reset_finish(guc);
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.h b/drivers/gpu/drm/i915/gt/uc/intel_uc.h
index eaa3202192ac..91315e3f1c58 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.h
@@ -30,6 +30,8 @@ struct intel_uc {
 
 	/* Snapshot of GuC log from last failed load */
 	struct drm_i915_gem_object *load_err_log;
+
+	bool reset_in_progress;
 };
 
 void intel_uc_init_early(struct intel_uc *uc);
-- 
2.38.1