Hi, there are some typos in the documentation and comments (see below). On 13.06.22 at 09:52, Ilpo Järvinen wrote: > -5. References > +5. Multipoint Addressing > +======================== > + > + The Linux kernel provides addressiong mode for multipoint RS-485 serial addressiong -> addressing > + communications line. The addressing mode is enabled with SER_RS485_ADDRB > + flag in serial_rs485. Struct serial_rs485 fhas two additional flags and fhas -> has > + fields for enabling reveive and destination addresses. reveive -> receive > + > + Address mode flags: > + - SER_RS485_ADDRB: Enabled addressing mode (sets also ADDRB in termios). > + - SER_RS485_ADDR_RECV: Receive (filter) address enabled. > + - SER_RS485_ADDR_DEST: Set destination address. > + > + Address fields (enabled with corresponding SER_RS485_ADDR_* flag): > + - addr_recv: Receive address. > + - addr_dest: Destination address. > + > + Once a receive address is set, the communication can occur only with the > + particular device and other peers are filtered out. It is left up to the > + receiver side to enforce the filtering. Receive address will be cleared > + if SER_RS485_ADDR_RECV is not set. > + > + Note: not all devices supporting RS485 support multipoint addressing. > + > +6. References > ============= > > [1] include/uapi/linux/serial.h > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 76bb1b77b06e..bc18018e8d4b 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -1294,6 +1294,17 @@ static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *r > if (flags & ~port->rs485_supported->flags) > return -EINVAL; > > + /* Asking for address w/o addressing mode? */ > + if (!(rs485->flags & SER_RS485_ADDRB) && > + (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST))) > + return -EINVAL; > + > + /* Address gived but not enabled? */ gived -> given Regards, Lino
