This adds hci_devcd_unregister() which can be called when driver is
removed, which will cleanup the devcoredump data and cancel delayed
dump_timeout work.

With BTNXPUART driver, it is observed that after FW dump, if driver is
removed and re-loaded, it creates hci1 interface instead of hci0
interface.

But after DEVCD_TIMEOUT (5 minutes) if driver is re-loaded, hci0 is
created. This is because after FW dump, hci0 is not unregistered
properly for DEVCD_TIMEOUT.

With this patch, BTNXPUART is able to create hci0 after every FW dump
and driver reload.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
---
 include/net/bluetooth/coredump.h | 3 +++
 net/bluetooth/coredump.c         | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/net/bluetooth/coredump.h b/include/net/bluetooth/coredump.h
index 72f51b587a04..bc8856e4bfe7 100644
--- a/include/net/bluetooth/coredump.h
+++ b/include/net/bluetooth/coredump.h

@@ -66,6 +66,7 @@ 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);
+void hci_devcd_unregister(struct hci_dev *hdev);
 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);

@@ -85,6 +86,8 @@ static inline int hci_devcd_register(struct hci_dev *hdev, coredump_t coredump,
        return -EOPNOTSUPP;
 }

+static inline void hci_devcd_unregister(struct hci_dev *hdev) {}
+
 static inline int hci_devcd_init(struct hci_dev *hdev, u32 dump_size)
 {
        return -EOPNOTSUPP;

diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
index 819eacb38762..dd7bd40e3eba 100644
--- a/net/bluetooth/coredump.c
+++ b/net/bluetooth/coredump.c

@@ -442,6 +442,14 @@ int hci_devcd_register(struct hci_dev *hdev, coredump_t coredump,
 }
 EXPORT_SYMBOL(hci_devcd_register);

+void hci_devcd_unregister(struct hci_dev *hdev)
+{
+       cancel_delayed_work(&hdev->dump.dump_timeout);
+       skb_queue_purge(&hdev->dump.dump_q);
+       dev_coredump_put(&hdev->dev);
+}
+EXPORT_SYMBOL_GPL(hci_devcd_unregister);