diff options
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index d4cca5bdaf1c..556f50aa1b58 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -130,6 +130,9 @@ static void uart_start(struct tty_struct *tty) struct uart_port *port; unsigned long flags; + if (!state) + return; + port = uart_port_lock(state, flags); __uart_start(tty); uart_port_unlock(port, flags); @@ -550,10 +553,12 @@ static int uart_put_char(struct tty_struct *tty, unsigned char c) int ret = 0; circ = &state->xmit; - if (!circ->buf) + port = uart_port_lock(state, flags); + if (!circ->buf) { + uart_port_unlock(port, flags); return 0; + } - port = uart_port_lock(state, flags); if (port && uart_circ_chars_free(circ) != 0) { circ->buf[circ->head] = c; circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); @@ -586,11 +591,13 @@ static int uart_write(struct tty_struct *tty, return -EL3HLT; } + port = uart_port_lock(state, flags); circ = &state->xmit; - if (!circ->buf) + if (!circ->buf) { + uart_port_unlock(port, flags); return 0; + } - port = uart_port_lock(state, flags); while (port) { c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); if (count < c) @@ -723,6 +730,9 @@ static void uart_unthrottle(struct tty_struct *tty) upstat_t mask = UPSTAT_SYNC_FIFO; struct uart_port *port; + if (!state) + return; + port = uart_port_ref(state); if (!port) return; |