[PATCH] Fix" introduced in 2.4.27pre2 for bluetooth hci_usb race causes kernel hang

tree c7737a3547f1135bd8ee8a0d559c43ef2fba484e
parent 284ce8b6e650e54a0348ebecb6c05d5acc899e56
author Marcel Holtmann <[email protected]> Wed, 13 Apr 2005 23:28:09 +0200
committer Marcelo Tosatti <[email protected]> Fri, 03 Jun 2005 00:03:57 -0300

[PATCH] Fix" introduced in 2.4.27pre2 for bluetooth hci_usb race causes kernel hang

> I have noticed a problem with a race condition fix introduced in
> 2.4.27-pre2 that causes the kernel to hang when disconnecting a
> Bluetooth USB dongle or doing 'hciconfig hci0 down'. No message is
> printed, the kernel just doesn't respond anymore.

if this works then we should do the same change in the bfusb driver. A
patch that fixes both drivers is attached.

 drivers/bluetooth/bfusb.c   |    3 +--
 drivers/bluetooth/hci_usb.c |    6 +++---
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c
--- a/drivers/bluetooth/bfusb.c
+++ b/drivers/bluetooth/bfusb.c
@@ -470,12 +470,11 @@ static int bfusb_close(struct hci_dev *h
 		return 0;
 
 	write_lock_irqsave(&bfusb->lock, flags);
+	write_unlock_irqrestore(&bfusb->lock, flags);
 
 	bfusb_unlink_urbs(bfusb);
 	bfusb_flush(hdev);
 
-	write_unlock_irqrestore(&bfusb->lock, flags);
-
 	MOD_DEC_USE_COUNT;
 
 	return 0;
diff --git a/drivers/bluetooth/hci_usb.c b/drivers/bluetooth/hci_usb.c
--- a/drivers/bluetooth/hci_usb.c
+++ b/drivers/bluetooth/hci_usb.c
@@ -398,13 +398,13 @@ static int hci_usb_close(struct hci_dev 
 
 	BT_DBG("%s", hdev->name);
 
+	/* Synchronize with completion handlers */
 	write_lock_irqsave(&husb->completion_lock, flags);
-	
+	write_unlock_irqrestore(&husb->completion_lock, flags);
+
 	hci_usb_unlink_urbs(husb);
 	hci_usb_flush(hdev);
 
-	write_unlock_irqrestore(&husb->completion_lock, flags);
-
 	MOD_DEC_USE_COUNT;
 	return 0;
 }