+static void max3107_handle_rx(struct max3107_port *s, unsigned int
rxlen) +{
+	unsigned int status, ch, flag;
+	struct tty_struct *tty = s->port.state->port.tty;

This all wants to be using tty_port_tty_get() and tty_kref_put - thats
a problem from the original of course. tty could also be NULL.

+	tty = port->state->port.tty;
+	if (!tty)
+		return;

This seems to be a meaninless test ?

+
+	/* Word size */
+	if ((termios->c_cflag & CSIZE) == CS7)
+		lcr = MAX3107_LCR_WORD_LEN_7;
+	else
+		lcr = MAX3107_LCR_WORD_LEN_8;

Should also write back the word size actually used if we can't see that
which was requested (ie mask ~CSIZE and | CS8 in the CS5/6 case)

+static volatile int driver_registered = 0;

Shouldn't need a volatile. Module load/unload are serialized for
obvious reasons.

Looks a very improved driver.

Alan