--- a/drivers/tty/serial/8250/8250.h +++ b/drivers/tty/serial/8250/8250.h @@ -83,6 +83,7 @@ struct serial8250_config { #define UART_CAP_MINI BIT(17) /* Mini UART on BCM283X family lacks: * STOP PARITY EPAR SPAR WLEN5 WLEN6 */ +#define UART_CAP_NMOD (1 << 18) /* UART doesn't do termios */ #define UART_BUG_QUOT BIT(0) /* UART has buggy quot LSB */ #define UART_BUG_TXEN BIT(1) /* UART has buggy TX IIR status */ --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -288,7 +288,7 @@ static const struct serial8250_config ua .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, - .flags = UART_CAP_FIFO, + .flags = UART_CAP_FIFO | UART_CAP_NMOD, }, [PORT_NPCM] = { .name = "Nuvoton 16550", @@ -2764,6 +2764,11 @@ serial8250_do_set_termios(struct uart_po unsigned long flags; unsigned int baud, quot, frac = 0; + if (up->capabilities & UART_CAP_NMOD) { + termios->c_cflag = 0; + return; + } + if (up->capabilities & UART_CAP_MINI) { termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR); if ((termios->c_cflag & CSIZE) == CS5 ||