On Mon, Oct 02, 2023 at 09:19:26AM +0200, Jiri Slaby wrote: > On 02. 10. 23, 3:57, Crescent CY Hsieh wrote: > > MOXA PCIe boards have 4 serial interfaces and don't require additional > > stuff to switch between interfaces: > > > > - RS232 > > - RS422 > > - RS485_2W (half-duplex) > > - RS485_4W (full-duplex) > > > > By using ioctl command "TIOCRS485", it can switch between default > > interface and RS485 if supported. > > > > That means, for RS422/RS485 board, it can switch between RS422 and > > RS485 by setting the flags within struct serial_rs485. > > > > However, for the RS232/RS422/RS485 board, it can only switch between > > RS232 and RS485, there's no flag for switching interface into RS422. > > > > This patch adds a flag call "SER_RS422_ENALBED" in serial.h and modifies > > Hopefully not SER_RS422_ENALBED. What if I use an existing flag within struct serial_rs485 to represent RS422 as a workaround solution? > > @@ -1299,7 +1299,7 @@ static int uart_get_icount(struct tty_struct *tty, > > #define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \ > > SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \ > > - SER_RS485_TERMINATE_BUS) > > + SER_RS485_TERMINATE_BUS | SER_RS422_ENALBED) > > So have you tested this at all? I have tested it by switching the serial interface using TIOCSRS485 ioctl command, but it seems that I send the wrong patch which mistyping SER_RS422_ENABLED. --- Sincerely, Crescent CY Hsieh
