tty: Add function for handling flow control chars

Move receive path flow control character handling to own function.

No functional changes.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220411094859.10894-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index bdc314aeab88671f37b64b547a5dbb1244ae05bb..88af1cdd2fd15c161a85dc45dec1d82e7758fe03 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1220,21 +1220,28 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
                process_echoes(tty);
 }
 
+/* Returns true if c is consumed as flow-control character */
+static bool n_tty_receive_char_flow_ctrl(struct tty_struct *tty, unsigned char c)
+{
+       if (c == START_CHAR(tty)) {
+               start_tty(tty);
+               process_echoes(tty);
+               return true;
+       }
+       if (c == STOP_CHAR(tty)) {
+               stop_tty(tty);
+               return true;
+       }
+
+       return false;
+}
+
 static void n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 {
        struct n_tty_data *ldata = tty->disc_data;
 
-       if (I_IXON(tty)) {
-               if (c == START_CHAR(tty)) {
-                       start_tty(tty);
-                       process_echoes(tty);
-                       return;
-               }
-               if (c == STOP_CHAR(tty)) {
-                       stop_tty(tty);
-                       return;
-               }
-       }
+       if (I_IXON(tty) && n_tty_receive_char_flow_ctrl(tty, c))
+               return;
 
        if (L_ISIG(tty)) {
                if (c == INTR_CHAR(tty)) {