[Intel-gfx] [RFC PATCH 72/97] drm/i915/guc: Don't complain about reset races

[Matthew Brost]

From: John Harrison <John.C.Harrison at Intel.com>

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 at Intel.com>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
 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 d5b326d4e250..1c240ff8dec9 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -718,7 +718,10 @@ 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 7035aa727e04..8c681fc49638 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;
+
 	/* Firmware expected to be running when this function is called */
 	if (!intel_guc_is_ready(guc))
 		goto sanitize;
@@ -574,6 +576,8 @@ 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);
-- 
2.28.0