Bluetooth: hci_uart: fix race during initialization

'hci_register_dev()' calls power up function, which is executed by
kworker - 'hci_power_on()'. This function does access to bluetooth chip
using callbacks from 'hci_ldisc.c', for example 'hci_uart_send_frame()'.
Now 'hci_uart_send_frame()' checks 'HCI_UART_PROTO_READY' bit set, and
if not - it fails. Problem is that 'HCI_UART_PROTO_READY' is set after
'hci_register_dev()', and there is tiny chance that 'hci_power_on()' will
be executed before setting this bit. In that case HCI init logic fails.

Patch moves setting of 'HCI_UART_PROTO_READY' before calling function
'hci_uart_register_dev()'.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index d2d6ba8d2f8b1cc583ed5aa54f1a0defa4ca3e4d..b955dc96b483af4671acfb7fd307346dfabeb9fa 100644 (file)
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -707,12 +707,13 @@ static int hci_uart_set_proto(struct hci_uart *hu, int id)
 
        hu->proto = p;
 
+       set_bit(HCI_UART_PROTO_READY, &hu->flags);
+
        err = hci_uart_register_dev(hu);
        if (err) {
                return err;
        }
 
-       set_bit(HCI_UART_PROTO_READY, &hu->flags);
        return 0;
 }