2 files changed, 45 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 08cf355e2e56..936b63483e96 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -126,7 +126,9 @@ static void guc_ct_fini(struct drm_device *drm, void *arg)
 	xa_destroy(&ct->fence_lookup);
 }
 
+static void receive_g2h(struct xe_guc_ct *ct);
 static void g2h_worker_func(struct work_struct *w);
+static void safe_mode_worker_func(struct work_struct *w);
 
 static void primelockdep(struct xe_guc_ct *ct)
 {
@@ -155,6 +157,7 @@ int xe_guc_ct_init(struct xe_guc_ct *ct)
 	spin_lock_init(&ct->fast_lock);
 	xa_init(&ct->fence_lookup);
 	INIT_WORK(&ct->g2h_worker, g2h_worker_func);
+	INIT_DELAYED_WORK(&ct->safe_mode_worker,  safe_mode_worker_func);
 	init_waitqueue_head(&ct->wq);
 	init_waitqueue_head(&ct->g2h_fence_wq);
 
@@ -321,6 +324,42 @@ static void xe_guc_ct_set_state(struct xe_guc_ct *ct,
 	mutex_unlock(&ct->lock);
 }
 
+static bool ct_needs_safe_mode(struct xe_guc_ct *ct)
+{
+	return !pci_dev_msi_enabled(to_pci_dev(ct_to_xe(ct)->drm.dev));
+}
+
+static bool ct_restart_safe_mode_worker(struct xe_guc_ct *ct)
+{
+	if (!ct_needs_safe_mode(ct))
+		return false;
+
+	queue_delayed_work(ct->g2h_wq, &ct->safe_mode_worker, HZ / 10);
+	return true;
+}
+
+static void safe_mode_worker_func(struct work_struct *w)
+{
+	struct xe_guc_ct *ct = container_of(w, struct xe_guc_ct, safe_mode_worker.work);
+
+	receive_g2h(ct);
+
+	if (!ct_restart_safe_mode_worker(ct))
+		xe_gt_dbg(ct_to_gt(ct), "GuC CT safe-mode canceled\n");
+}
+
+static void ct_enter_safe_mode(struct xe_guc_ct *ct)
+{
+	if (ct_restart_safe_mode_worker(ct))
+		xe_gt_dbg(ct_to_gt(ct), "GuC CT safe-mode enabled\n");
+}
+
+static void ct_exit_safe_mode(struct xe_guc_ct *ct)
+{
+	if (cancel_delayed_work_sync(&ct->safe_mode_worker))
+		xe_gt_dbg(ct_to_gt(ct), "GuC CT safe-mode disabled\n");
+}
+
 int xe_guc_ct_enable(struct xe_guc_ct *ct)
 {
 	struct xe_device *xe = ct_to_xe(ct);
@@ -350,6 +389,9 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
 	wake_up_all(&ct->wq);
 	xe_gt_dbg(gt, "GuC CT communication channel enabled\n");
 
+	if (ct_needs_safe_mode(ct))
+		ct_enter_safe_mode(ct);
+
 	return 0;
 
 err_out:
@@ -373,6 +415,7 @@ static void stop_g2h_handler(struct xe_guc_ct *ct)
 void xe_guc_ct_disable(struct xe_guc_ct *ct)
 {
 	xe_guc_ct_set_state(ct, XE_GUC_CT_STATE_DISABLED);
+	ct_exit_safe_mode(ct);
 	stop_g2h_handler(ct);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_guc_ct_types.h b/drivers/gpu/drm/xe/xe_guc_ct_types.h
index fede4c6e93cb..761cb9031298 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct_types.h
+++ b/drivers/gpu/drm/xe/xe_guc_ct_types.h
@@ -110,6 +110,8 @@ struct xe_guc_ct {
 	u32 g2h_outstanding;
 	/** @g2h_worker: worker to process G2H messages */
 	struct work_struct g2h_worker;
+	/** @safe_mode_worker: worker to check G2H messages with IRQ disabled */
+	struct delayed_work safe_mode_worker;
 	/** @state: CT state */
 	enum xe_guc_ct_state state;
 	/** @fence_seqno: G2H fence seqno - 16 bits used by CT */