[PATCH 7/7] drm/xe: Check for GuC responses on disabling scheduling

[Stuart Summers <stuart.summers@intel.com>]

Currently if the GuC becomes unresponsive during a schedule
disable event, after we send the CT request, the driver
doesn't have a good way to recover. In most other cases,
we explicitly wait for GuC to respond by checking either
pending_enable, pending_disable, or some other state change
that we expect to be set after the response from GuC is
received for that particular request. Add a similar check
on the schedule disable side and make sure the queue state
for the queue being disabled is reset properly in that case.

v2: Only call the deregistration sequence since in this
    case the scheduling handler should be reset during
    the GT reset.
    By doing that, we don't need a way to track the scheduling
    disable request handler for that queue, making this sequence
    simpler. As a result, don't mark the queue as banned.

Signed-off-by: Stuart Summers <stuart.summers@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_submit.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index 5ec1e4a83d68..6ba4a29007eb 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -918,6 +918,8 @@ int xe_guc_read_stopped(struct xe_guc *guc)
 		GUC_CONTEXT_##enable_disable,				\
 	}
 
+static void handle_deregister_done(struct xe_guc *guc, struct xe_exec_queue *q);
+
 static void disable_scheduling_deregister(struct xe_guc *guc,
 					  struct xe_exec_queue *q)
 {
@@ -955,6 +957,17 @@ static void disable_scheduling_deregister(struct xe_guc *guc,
 	xe_guc_ct_send(&guc->ct, action, ARRAY_SIZE(action),
 		       G2H_LEN_DW_SCHED_CONTEXT_MODE_SET +
 		       G2H_LEN_DW_DEREGISTER_CONTEXT, 2);
+
+	ret = wait_event_timeout(guc->ct.wq,
+				 !exec_queue_pending_disable(q) ||
+				 xe_guc_read_stopped(guc),
+				 HZ * 5);
+	if (!ret || xe_guc_read_stopped(guc)) {
+		xe_gt_warn(guc_to_gt(guc), "Schedule disable failed to respond");
+		handle_deregister_done(guc, q);
+		xe_gt_reset_async(q->gt);
+	}
+
 }
 
 static void xe_guc_exec_queue_trigger_cleanup(struct xe_exec_queue *q)
-- 
2.34.1