'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@xxxxxxxxxxxxxxxxx> --- Changelog v1->v2: * Move 'set_bit()' before 'hci_uart_register_dev()' instead of adding new bit 'HCI_UART_PROTO_INIT'. drivers/bluetooth/hci_ldisc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 30192bb083549..07b9aa09bbe2e 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -704,12 +704,13 @@ 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; } -- 2.30.1