mxser: extract mxser_receive_chars_new

Extract the new handling of receive chars (using the MUST chip
enhancements) into a separate function. This eliminates the need for the
intr_old label and makes the code of mxser_receive_chars more compact.
In the next step, we will extract the old handling too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index df59ca88acab8dc0adf5b326d29c5de84314b419..a321aba24d588a56fe828271beffd9be375a3df9 100644 (file)
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2055,10 +2055,41 @@ static int mxser_rs_break(struct tty_struct *tty, int break_state)
        return 0;
 }
 
+static bool mxser_receive_chars_new(struct tty_struct *tty,
+               struct mxser_port *port, u8 status, int *cnt)
+{
+       enum mxser_must_hwid hwid = port->board->must_hwid;
+       u8 gdl;
+
+       if (hwid == MOXA_OTHER_UART)
+               return false;
+       if (status & UART_LSR_SPECIAL)
+               return false;
+       if (hwid == MOXA_MUST_MU860_HWID && (status & MOXA_MUST_LSR_RERR))
+               return false;
+       if (status & MOXA_MUST_LSR_RERR)
+               return false;
+
+       gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
+       if (hwid == MOXA_MUST_MU150_HWID)
+               gdl &= MOXA_MUST_GDL_MASK;
+
+       if (gdl >= tty->receive_room && !port->ldisc_stop_rx)
+               mxser_stoprx(tty);
+
+       while (gdl--) {
+               u8 ch = inb(port->ioaddr + UART_RX);
+               tty_insert_flip_char(&port->port, ch, 0);
+               (*cnt)++;
+       }
+
+       return true;
+}
+
 static u8 mxser_receive_chars(struct tty_struct *tty,
                struct mxser_port *port, u8 status)
 {
-       unsigned char ch, gdl;
+       unsigned char ch;
        int ignored = 0;
        int cnt = 0;
        int recv_room;
@@ -2067,32 +2098,9 @@ static u8 mxser_receive_chars(struct tty_struct *tty,
        recv_room = tty->receive_room;
        if (recv_room == 0 && !port->ldisc_stop_rx)
                mxser_stoprx(tty);
-       if (port->board->must_hwid != MOXA_OTHER_UART) {
-
-               if (status & UART_LSR_SPECIAL)
-                       goto intr_old;
-               if (port->board->must_hwid == MOXA_MUST_MU860_HWID &&
-                               (status & MOXA_MUST_LSR_RERR))
-                       goto intr_old;
-               if (status & MOXA_MUST_LSR_RERR)
-                       goto intr_old;
-
-               gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
-
-               if (port->board->must_hwid == MOXA_MUST_MU150_HWID)
-                       gdl &= MOXA_MUST_GDL_MASK;
-               if (gdl >= recv_room) {
-                       if (!port->ldisc_stop_rx)
-                               mxser_stoprx(tty);
-               }
-               while (gdl--) {
-                       ch = inb(port->ioaddr + UART_RX);
-                       tty_insert_flip_char(&port->port, ch, 0);
-                       cnt++;
-               }
+
+       if (mxser_receive_chars_new(tty, port, status, &cnt))
                goto end_intr;
-       }
-intr_old:
 
        do {
                if (max-- < 0)