[PATCH 03/11] Bluetooth: coredump: Introduce and apply hci_devcd_state_name()

[Zijun Hu <zijun.hu@oss.qualcomm.com>]

Introduce hci_devcd_state_name() to describe the devcoredump state by a
string name instead of a plain number, for several reasons:

1) Applying it in coredump.c makes the devcoredump state in log messages
   more readable than a plain number.
2) Transport drivers may need to show the devcoredump state name too.
3) In future, the universal state name could be notified to userspace
   via uevent, allowing a universal application (e.g. a daemon) to be
   developed to save the coredump, which is otherwise discarded by the
   device coredump core after 5 minutes (DEVCD_TIMEOUT); see
   nxp_coredump_notify().

Also drop a trailing space from two bt_dev_dbg() format strings while
applying it in coredump.c.

Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
---
Previous version:
https://lore.kernel.org/all/20260713-btusb_prep_qcc2072-v2-1-bbcb651285f2@oss.qualcomm.com

Changes since previous version:
- Improve commit title and message.
---
 include/net/bluetooth/coredump.h |  7 +++++++
 net/bluetooth/coredump.c         | 45 +++++++++++++++++++++++++++++++++-------
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/include/net/bluetooth/coredump.h b/include/net/bluetooth/coredump.h
index 72f51b587a04..ab85a6adfffd 100644
--- a/include/net/bluetooth/coredump.h
+++ b/include/net/bluetooth/coredump.h
@@ -55,30 +55,37 @@ struct hci_devcoredump {
 
 	coredump_t		coredump;
 	dmp_hdr_t		dmp_hdr;
 	notify_change_t		notify_change;
 };
 
 #ifdef CONFIG_DEV_COREDUMP
 
+const char *hci_devcd_state_name(enum devcoredump_state state);
+
 void hci_devcd_reset(struct hci_dev *hdev);
 void hci_devcd_rx(struct work_struct *work);
 void hci_devcd_timeout(struct work_struct *work);
 
 int hci_devcd_register(struct hci_dev *hdev, coredump_t coredump,
 		       dmp_hdr_t dmp_hdr, notify_change_t notify_change);
 int hci_devcd_init(struct hci_dev *hdev, u32 dump_size);
 int hci_devcd_append(struct hci_dev *hdev, struct sk_buff *skb);
 int hci_devcd_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len);
 int hci_devcd_complete(struct hci_dev *hdev);
 int hci_devcd_abort(struct hci_dev *hdev);
 
 #else
 
+static inline const char *hci_devcd_state_name(enum devcoredump_state state)
+{
+	return "";
+}
+
 static inline void hci_devcd_reset(struct hci_dev *hdev) {}
 static inline void hci_devcd_rx(struct work_struct *work) {}
 static inline void hci_devcd_timeout(struct work_struct *work) {}
 
 static inline int hci_devcd_register(struct hci_dev *hdev, coredump_t coredump,
 				     dmp_hdr_t dmp_hdr,
 				     notify_change_t notify_change)
 {
diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
index c0f027fab583..913bbba559f8 100644
--- a/net/bluetooth/coredump.c
+++ b/net/bluetooth/coredump.c
@@ -25,18 +25,19 @@ struct hci_devcoredump_skb_pattern {
 	u8 pattern;
 	u32 len;
 } __packed;
 
 #define hci_dmp_cb(skb)	((struct hci_devcoredump_skb_cb *)((skb)->cb))
 
 #define DBG_UNEXPECTED_STATE() \
 	bt_dev_dbg(hdev, \
-		   "Unexpected packet (%d) for state (%d). ", \
-		   hci_dmp_cb(skb)->pkt_type, hdev->dump.state)
+		   "Unexpected packet (%d) for state %s.", \
+		   hci_dmp_cb(skb)->pkt_type, \
+		   hci_devcd_state_name(hdev->dump.state))
 
 #define MAX_DEVCOREDUMP_HDR_SIZE	512	/* bytes */
 
 static int hci_devcd_update_hdr_state(char *buf, size_t size, int state)
 {
 	int len = 0;
 
 	if (!buf)
@@ -45,18 +46,19 @@ static int hci_devcd_update_hdr_state(char *buf, size_t size, int state)
 	len = scnprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);
 
 	return len + 1; /* scnprintf adds \0 at the end upon state rewrite */
 }
 
 /* Call with hci_dev_lock only. */
 static int hci_devcd_update_state(struct hci_dev *hdev, int state)
 {
-	bt_dev_dbg(hdev, "Updating devcoredump state from %d to %d.",
-		   hdev->dump.state, state);
+	bt_dev_dbg(hdev, "Updating devcoredump state from %s to %s.",
+		   hci_devcd_state_name(hdev->dump.state),
+		   hci_devcd_state_name(state));
 
 	hdev->dump.state = state;
 
 	return hci_devcd_update_hdr_state(hdev->dump.head,
 					  hdev->dump.alloc_size, state);
 }
 
 static int hci_devcd_mkheader(struct hci_dev *hdev, struct sk_buff *skb)
@@ -240,17 +242,17 @@ static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev,
 		bt_dev_dbg(hdev, "Failed to set pattern");
 }
 
 static void hci_devcd_dump(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;
 	u32 size;
 
-	bt_dev_dbg(hdev, "state %d", hdev->dump.state);
+	bt_dev_dbg(hdev, "state %s", hci_devcd_state_name(hdev->dump.state));
 
 	size = hdev->dump.tail - hdev->dump.head;
 
 	/* Send a copy to monitor as a diagnostic packet */
 	skb = bt_skb_alloc(size, GFP_ATOMIC);
 	if (skb) {
 		skb_put_data(skb, hdev->dump.head, size);
 		hci_recv_diag(hdev, skb);
@@ -363,18 +365,19 @@ void hci_devcd_rx(struct work_struct *work)
 			hci_devcd_handle_pkt_complete(hdev, skb);
 			break;
 
 		case HCI_DEVCOREDUMP_PKT_ABORT:
 			hci_devcd_handle_pkt_abort(hdev, skb);
 			break;
 
 		default:
-			bt_dev_dbg(hdev, "Unknown packet (%d) for state (%d). ",
-				   hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
+			bt_dev_dbg(hdev, "Unknown packet (%d) for state %s.",
+				   hci_dmp_cb(skb)->pkt_type,
+				   hci_devcd_state_name(hdev->dump.state));
 			break;
 		}
 
 		hci_dev_unlock(hdev);
 		kfree_skb(skb);
 
 		/* Notify the driver about any state changes before resetting
 		 * the state machine
@@ -544,8 +547,36 @@ int hci_devcd_abort(struct hci_dev *hdev)
 	hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_ABORT;
 
 	skb_queue_tail(&hdev->dump.dump_q, skb);
 	queue_work(hdev->workqueue, &hdev->dump.dump_rx);
 
 	return 0;
 }
 EXPORT_SYMBOL(hci_devcd_abort);
+
+const char *hci_devcd_state_name(enum devcoredump_state state)
+{
+	const char *state_name = "Unknown";
+
+	switch (state) {
+	case HCI_DEVCOREDUMP_IDLE:
+		state_name = "IDLE";
+		break;
+	case HCI_DEVCOREDUMP_ACTIVE:
+		state_name = "ACTIVE";
+		break;
+	case HCI_DEVCOREDUMP_DONE:
+		state_name = "DONE";
+		break;
+	case HCI_DEVCOREDUMP_ABORT:
+		state_name = "ABORT";
+		break;
+	case HCI_DEVCOREDUMP_TIMEOUT:
+		state_name = "TIMEOUT";
+		break;
+	default:
+		break;
+	}
+
+	return state_name;
+}
+EXPORT_SYMBOL(hci_devcd_state_name);

-- 
2.34.1