mpc52xx_uart_int and __uart_put_char both try to acquire the port->lock. Therefore the function sequence of:
mpc52xx_uart_int--> ...-->flush_to_ldisc-->...-->__uart_put_char can potentially trigger a deadlock. To avoid this deadlock a fix similar to that found in the 8250.c serial driver is applied. The deadlock is avoided by releasing the lock before pushing a buffer and reacquiring it when completed. Signed-off-by: Andrew Liu <[EMAIL PROTECTED]> diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c index d93b357..5f95e53 100644 --- a/drivers/serial/mpc52xx_uart.c +++ b/drivers/serial/mpc52xx_uart.c @@ -783,7 +783,9 @@ mpc52xx_uart_int_rx_chars(struct uart_port *port) } } + spin_unlock(&port->lock); tty_flip_buffer_push(tty); + spin_lock(&port->lock); return psc_ops->raw_rx_rdy(port); } _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev