diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index f068b8d7840a..1902f29444a1 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -107,11 +107,23 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value) return value; } +/* + * This function is being called as part of the uart_port::serial_out() + * routine. Hence, it must not call serial_port_out() or serial_out() + * against the modified registers here, i.e. LCR. + */ static void dw8250_force_idle(struct uart_port *p) { struct uart_8250_port *up = up_to_u8250p(p); unsigned int lsr; + /* + * The following call currently performs serial_out() + * against the FCR register. Because it differs to LCR + * there will be no infinite loop, but if it ever gets + * modified, we might need a new custom version of it + * that avoids infinite recursion. + */ serial8250_clear_and_reinit_fifos(up); /* @@ -128,6 +140,11 @@ static void dw8250_force_idle(struct uart_port *p) serial_port_in(p, UART_RX); } +/* + * This function is being called as part of the uart_port::serial_out() + * routine. Hence, it must not call serial_port_out() or serial_out() + * against the modified registers here, i.e. LCR. + */ static void dw8250_check_lcr(struct uart_port *p, int offset, int value) { struct dw8250_data *d = to_dw8250_data(p->private_data); |