@@ -118,10 +118,6 @@ static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
int hci_uart_tx_wakeup(struct hci_uart *hu)
{
- struct tty_struct *tty = hu->tty;
- struct hci_dev *hdev = hu->hdev;
- struct sk_buff *skb;
-
if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
return 0;
@@ -129,6 +125,22 @@ int hci_uart_tx_wakeup(struct hci_uart *hu)
BT_DBG("");
+ schedule_work(&hu->write_work);
+
+ return 0;
+}
+
+static void hci_uart_write_work(struct work_struct *work)
+{
+ struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
+ struct tty_struct *tty = hu->tty;
+ struct hci_dev *hdev = hu->hdev;
+ struct sk_buff *skb;
+
+ /* REVISIT: should we cope with bad skbs or ->write() returning
+ * and error value ?
+ */
+
restart:
clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
@@ -153,7 +165,6 @@ restart:
goto restart;
clear_bit(HCI_UART_SENDING, &hu->tx_state);
- return 0;
}
static void hci_uart_init_work(struct work_struct *work)
@@ -289,6 +300,7 @@ static int hci_uart_tty_open(struct tty_struct *tty)
tty->receive_room = 65536;
INIT_WORK(&hu->init_ready, hci_uart_init_work);
+ INIT_WORK(&hu->write_work, hci_uart_write_work);
spin_lock_init(&hu->rx_lock);
@@ -326,6 +338,8 @@ static void hci_uart_tty_close(struct tty_struct *tty)
if (hdev)
hci_uart_close(hdev);
+ cancel_work_sync(&hu->write_work);
+
if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
if (hdev) {
if (test_bit(HCI_UART_REGISTERED, &hu->flags))
@@ -68,6 +68,7 @@ struct hci_uart {
unsigned long hdev_flags;
struct work_struct init_ready;
+ struct work_struct write_work;
struct hci_uart_proto *proto;
void *priv;
This is a note to let you know that I have just added a patch titled bluetooth: hci_ldisc: fix deadlock condition to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.27. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 202491b2b56b7bded4dea0a754a6c93d8826424d Mon Sep 17 00:00:00 2001 From: Felipe Balbi <balbi@ti.com> Date: Wed, 23 Apr 2014 09:58:26 -0500 Subject: bluetooth: hci_ldisc: fix deadlock condition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit da64c27d3c93ee9f89956b9de86c4127eb244494 upstream. LDISCs shouldn't call tty->ops->write() from within ->write_wakeup(). ->write_wakeup() is called with port lock taken and IRQs disabled, tty->ops->write() will try to acquire the same port lock and we will deadlock. Acked-by: Marcel Holtmann <marcel@holtmann.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Reported-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Tested-by: Andreas Bießmann <andreas@biessmann.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/bluetooth/hci_ldisc.c | 24 +++++++++++++++++++----- drivers/bluetooth/hci_uart.h | 1 + 2 files changed, 20 insertions(+), 5 deletions(-) -- 1.9.1