[PATCH] drm/xe: Make sysfs gt force reset synchronous

[Karthik Poosa]

Wait for gt reset to complete before returning from force_reset
sysfs call. Without this igt test freq_reset_multiple fails
sporadically in case xe_guc_pc is not started.

Testcase: igt at xe_guc_pc@freq_reset_multiple
Signed-off-by: Karthik Poosa <karthik.poosa at intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar at intel.com>
---
 drivers/gpu/drm/xe/xe_gt.c         |  3 +++
 drivers/gpu/drm/xe/xe_gt_debugfs.c | 10 ++++++++++
 drivers/gpu/drm/xe/xe_gt_types.h   |  3 +++
 3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index dfd9cf01a5d5..eb7552b6dfa5 100644
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -65,6 +65,7 @@ struct xe_gt *xe_gt_alloc(struct xe_tile *tile)
 
 	gt->tile = tile;
 	gt->ordered_wq = alloc_ordered_workqueue("gt-ordered-wq", 0);
+	init_completion(&gt->reset_done);
 
 	return gt;
 }
@@ -647,6 +648,8 @@ static int gt_reset(struct xe_gt *gt)
 	xe_device_mem_access_put(gt_to_xe(gt));
 	XE_WARN_ON(err);
 
+	complete(&gt->reset_done);
+
 	xe_gt_info(gt, "reset done\n");
 
 	return 0;
diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
index c4b67cf09f8f..f4ff0eef0468 100644
--- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
@@ -23,6 +23,8 @@
 #include "xe_uc_debugfs.h"
 #include "xe_wa.h"
 
+#define XE_GT_RESET_TIMEOUT_MS	(msecs_to_jiffies(5 * 1000))
+
 static struct xe_gt *node_to_gt(struct drm_info_node *node)
 {
 	return node->info_ent->data;
@@ -58,9 +60,17 @@ static int hw_engines(struct seq_file *m, void *data)
 static int force_reset(struct seq_file *m, void *data)
 {
 	struct xe_gt *gt = node_to_gt(m->private);
+	struct xe_device *xe = gt_to_xe(gt);
+	unsigned long timeout;
 
 	xe_gt_reset_async(gt);
 
+	timeout = wait_for_completion_timeout(&gt->reset_done, XE_GT_RESET_TIMEOUT_MS);
+	if (timeout == 0) {
+		drm_err(&xe->drm, "gt reset timed out");
+		return -ETIMEDOUT;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/xe/xe_gt_types.h b/drivers/gpu/drm/xe/xe_gt_types.h
index f74684660475..6f2fb9e3cfea 100644
--- a/drivers/gpu/drm/xe/xe_gt_types.h
+++ b/drivers/gpu/drm/xe/xe_gt_types.h
@@ -358,6 +358,9 @@ struct xe_gt {
 		/** @oob: bitmap with active OOB workaroudns */
 		unsigned long *oob;
 	} wa_active;
+
+	/** @reset_done : Completion of GT reset */
+	struct completion reset_done;
 };
 
 #endif
-- 
2.25.1