From 39e01d0812918fab42719b8a80f8c01a1bd0fc32 Mon Sep 17 00:00:00 2001
From: Dustin Brown <dustinb@codeaurora.org>
Date: Thu, 4 Oct 2018 13:32:50 -0700
Subject: [PATCH] qcacld-3.0: Add operation timeout detection to DSC

In order to catch and debug long running or stuck operations, add a
watchdog timer to Driver Synchronization Core (DSC) operation start/stop
call pairs. If the timer expires, panic the driver for offline
debugging.

Change-Id: If93914178622b993fb09c7330fded2e9bc1c25d1
CRs-Fixed: 2328591
---
 components/dsc/src/__wlan_dsc.c | 23 +++++++++++++++++++++++
 components/dsc/src/__wlan_dsc.h |  4 ++++
 2 files changed, 27 insertions(+)

diff --git a/components/dsc/src/__wlan_dsc.c b/components/dsc/src/__wlan_dsc.c
index 25aad7846a68..e71b499b75f3 100644
--- a/components/dsc/src/__wlan_dsc.c
+++ b/components/dsc/src/__wlan_dsc.c
@@ -20,9 +20,18 @@
 #include "qdf_mem.h"
 #include "qdf_status.h"
 #include "qdf_str.h"
+#include "qdf_timer.h"
 #include "__wlan_dsc.h"
 
 #ifdef WLAN_DSC_DEBUG
+static void __dsc_dbg_op_timeout(void *opaque_op)
+{
+	struct dsc_op *op = opaque_op;
+
+	QDF_DEBUG_PANIC("Operation '%s' exceeded %ums",
+			op->func, DSC_OP_TIMEOUT_MS);
+}
+
 /**
  * __dsc_dbg_ops_init() - initialize debug ops data structures
  * @ops: the ops container to initialize
@@ -54,17 +63,29 @@ static inline void __dsc_dbg_ops_deinit(struct dsc_ops *ops)
  */
 static QDF_STATUS __dsc_dbg_ops_insert(struct dsc_ops *ops, const char *func)
 {
+	QDF_STATUS status;
 	struct dsc_op *op;
 
 	op = qdf_mem_malloc(sizeof(*op));
 	if (!op)
 		return QDF_STATUS_E_NOMEM;
 
+	status = qdf_timer_init(NULL, &op->timeout_timer, __dsc_dbg_op_timeout,
+				op, QDF_TIMER_TYPE_SW);
+	if (QDF_IS_STATUS_ERROR(status))
+		goto free_op;
+
 	op->func = func;
 
+	qdf_timer_start(&op->timeout_timer, DSC_OP_TIMEOUT_MS);
 	qdf_list_insert_back(&ops->list, &op->node);
 
 	return QDF_STATUS_SUCCESS;
+
+free_op:
+	qdf_mem_free(op);
+
+	return status;
 }
 
 /**
@@ -86,6 +107,8 @@ static void __dsc_dbg_ops_remove(struct dsc_ops *ops, const char *func)
 		/* this is safe because we cease iteration */
 		qdf_list_remove_node(&ops->list, &op->node);
 
+		qdf_timer_stop(&op->timeout_timer);
+		qdf_timer_free(&op->timeout_timer);
 		qdf_mem_free(op);
 
 		return;
diff --git a/components/dsc/src/__wlan_dsc.h b/components/dsc/src/__wlan_dsc.h
index 103413d0d4ea..40ff29752e6b 100644
--- a/components/dsc/src/__wlan_dsc.h
+++ b/components/dsc/src/__wlan_dsc.h
@@ -26,6 +26,7 @@
 #include "qdf_event.h"
 #include "qdf_list.h"
 #include "qdf_trace.h"
+#include "qdf_timer.h"
 #include "qdf_types.h"
 #include "wlan_dsc.h"
 
@@ -55,6 +56,7 @@ static inline bool __dsc_assert(const bool cond, const char *cond_str,
 
 #ifdef WLAN_DSC_DEBUG
 #define DSC_TRANS_TIMEOUT 120000 /* 2 minutes */
+#define DSC_OP_TIMEOUT_MS	(1 * 60 * 1000) /* 1 minute */
 #else
 #define DSC_TRANS_TIMEOUT 0 /* no timeout */
 #endif
@@ -63,10 +65,12 @@ static inline bool __dsc_assert(const bool cond, const char *cond_str,
 /**
  * struct dsc_op - list node for operation tracking information
  * @node: list node
+ * @timeout_timer: a timer used to detect operation timeouts
  * @func: name of the function the operation was started from
  */
 struct dsc_op {
 	qdf_list_node_t node;
+	qdf_timer_t timeout_timer;
 	const char *func;
 };
 #endif /* WLAN_DSC_DEBUG */