[Intel-gfx] [PATCH 4/7] drm/i915/uc: Stop talking with GuC when resetting

[Michal Wajdeczko]

Knowing that GuC will be reset soon, we may stop all communication
immediately without doing graceful cleanup as it is not needed.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_ct.h |  5 +++++
 drivers/gpu/drm/i915/intel_uc.c     | 13 ++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_ct.h b/drivers/gpu/drm/i915/intel_guc_ct.h
index f5e7f0663304..41ba593a4df7 100644
--- a/drivers/gpu/drm/i915/intel_guc_ct.h
+++ b/drivers/gpu/drm/i915/intel_guc_ct.h
@@ -96,4 +96,9 @@ void intel_guc_ct_fini(struct intel_guc_ct *ct);
 int intel_guc_ct_enable(struct intel_guc_ct *ct);
 void intel_guc_ct_disable(struct intel_guc_ct *ct);
 
+static inline void intel_guc_ct_stop(struct intel_guc_ct *ct)
+{
+	ct->host_channel.enabled = false;
+}
+
 #endif /* _INTEL_GUC_CT_H_ */
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 9d86cd831ea7..86edfa5ad72e 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -224,6 +224,17 @@ static int guc_enable_communication(struct intel_guc *guc)
 	return 0;
 }
 
+static void guc_stop_communication(struct intel_guc *guc)
+{
+	struct drm_i915_private *i915 = guc_to_i915(guc);
+
+	if (HAS_GUC_CT(i915))
+		intel_guc_ct_stop(&guc->ct);
+
+	guc->send = intel_guc_send_nop;
+	guc->handler = intel_guc_to_host_event_handler_nop;
+}
+
 static void guc_disable_communication(struct intel_guc *guc)
 {
 	struct drm_i915_private *i915 = guc_to_i915(guc);
@@ -488,7 +499,7 @@ void intel_uc_reset_prepare(struct drm_i915_private *i915)
 	if (!USES_GUC(i915))
 		return;
 
-	guc_disable_communication(guc);
+	guc_stop_communication(guc);
 	__uc_sanitize(i915);
 }
 
-- 
2.19.2