[PATCH v13 4/4] drm/xe/ras: Use fault-inject to trigger cold-reset wedge

Use the fault-inject framework to trigger the cold-reset
wedge path (punit_error_handler()) for testing the
wedge/recovery flow.

Usage:
  echo 100 > .../wedge_cold_reset/probability
  echo 1   > .../wedge_cold_reset/times

Signed-off-by: Mallesh Koujalagi <[email protected]>
---
v13:
- Rename inject_punit_error to wedge_cold_reset. (Riana)
- Sashiko corner case issue addressed with
  commit 20bc4883c7c0 ("drm/xe/ras: Fix boot-time ras error processing").
---
 drivers/gpu/drm/xe/xe_debugfs.c | 4 ++++
 drivers/gpu/drm/xe/xe_debugfs.h | 2 ++
 drivers/gpu/drm/xe/xe_ras.c     | 7 +++++++
 3 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
index 8de78cd0aa03..acd34cc5dcbd 100644
--- a/drivers/gpu/drm/xe/xe_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_debugfs.c
@@ -42,6 +42,7 @@
 
 DECLARE_FAULT_ATTR(gt_reset_failure);
 DECLARE_FAULT_ATTR(inject_csc_hw_error);
+DECLARE_FAULT_ATTR(wedge_cold_reset);
 
 static bool csc_hw_error_available(struct xe_device *xe)
 {
@@ -62,6 +63,8 @@ static struct {
 	{ .name = "inject_csc_hw_error",
 	  .attr = &inject_csc_hw_error,
 	  .is_visible = csc_hw_error_available },
+	{ .name = "wedge_cold_reset",
+	  .attr = &wedge_cold_reset },
 };
 
 /*
@@ -76,6 +79,7 @@ bool xe_fault_##name(void)				\
 
 FAULT_ACTION(gt_reset, gt_reset_failure)
 FAULT_ACTION(csc_hw_error, inject_csc_hw_error)
+FAULT_ACTION(wedge_cold_reset, wedge_cold_reset)
 
 static void xe_fault_inject_debugfs_register(struct xe_device *xe,
 					     struct dentry *root)
diff --git a/drivers/gpu/drm/xe/xe_debugfs.h b/drivers/gpu/drm/xe/xe_debugfs.h
index cd56f7442b99..0dcd28fd7dc0 100644
--- a/drivers/gpu/drm/xe/xe_debugfs.h
+++ b/drivers/gpu/drm/xe/xe_debugfs.h
@@ -13,10 +13,12 @@ struct xe_device;
 #ifdef CONFIG_DEBUG_FS
 bool xe_fault_gt_reset(void);
 bool xe_fault_csc_hw_error(void);
+bool xe_fault_wedge_cold_reset(void);
 void xe_debugfs_register(struct xe_device *xe);
 #else
 static inline bool xe_fault_gt_reset(void) { return false; }
 static inline bool xe_fault_csc_hw_error(void) { return false; }
+static inline bool xe_fault_wedge_cold_reset(void) { return false; }
 static inline void xe_debugfs_register(struct xe_device *xe) { }
 #endif
 
diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
index 3033a377bace..7cd17f4b444a 100644
--- a/drivers/gpu/drm/xe/xe_ras.c
+++ b/drivers/gpu/drm/xe/xe_ras.c
@@ -3,6 +3,7 @@
  * Copyright © 2026 Intel Corporation
  */
 
+#include "xe_debugfs.h"
 #include "xe_device.h"
 #include "xe_drm_ras.h"
 #include "xe_pm.h"
@@ -415,6 +416,12 @@ enum xe_ras_recovery_action xe_ras_process_errors(struct xe_device *xe)
 	size_t rlen;
 	int ret;
 
+	if (xe_fault_wedge_cold_reset()) {
+		xe_err(xe, "[RAS]: cold-reset wedge injected\n");
+		punit_error_handler(xe);
+		return XE_RAS_RECOVERY_ACTION_DISCONNECT;
+	}
+
 	if (!xe->info.has_sysctrl)
 		return XE_RAS_RECOVERY_ACTION_RESET;
 
-- 
2.48.1