serial: 8250: extract serial8250_set_afe()

serial8250_do_set_termios() consists of many registers and up flags
settings. Extract all these into separate functions. This time, setting
of MCR for UART_CAP_AFE ports.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250611100319.186924-21-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 52385314c42645511ea983a0e8d86c04f2edbf21..b15371838366b8709758eb036f9bd5bd9ca109ac 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2704,6 +2704,22 @@ static void serial8250_set_trigger_for_slow_speed(struct uart_port *port, struct
        up->fcr |= UART_FCR_TRIGGER_1;
 }
 
+/*
+ * MCR-based auto flow control. When AFE is enabled, RTS will be deasserted when the receive FIFO
+ * contains more characters than the trigger, or the MCR RTS bit is cleared.
+ */
+static void serial8250_set_afe(struct uart_port *port, struct ktermios *termios)
+{
+       struct uart_8250_port *up = up_to_u8250p(port);
+
+       if (!(up->capabilities & UART_CAP_AFE))
+               return;
+
+       up->mcr &= ~UART_MCR_AFE;
+       if (termios->c_cflag & CRTSCTS)
+               up->mcr |= UART_MCR_AFE;
+}
+
 void
 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
                          const struct ktermios *old)
@@ -2729,21 +2745,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
        up->lcr = cval;                                 /* Save computed LCR */
        serial8250_set_trigger_for_slow_speed(port, termios, baud);
-
-       /*
-        * MCR-based auto flow control.  When AFE is enabled, RTS will be
-        * deasserted when the receive FIFO contains more characters than
-        * the trigger, or the MCR RTS bit is cleared.
-        */
-       if (up->capabilities & UART_CAP_AFE) {
-               up->mcr &= ~UART_MCR_AFE;
-               if (termios->c_cflag & CRTSCTS)
-                       up->mcr |= UART_MCR_AFE;
-       }
-
-       /*
-        * Update the per-port timeout.
-        */
+       serial8250_set_afe(port, termios);
        uart_update_timeout(port, termios->c_cflag, baud);
 
        /*