mxser: don't allocate MXSER_PORTS + 1

The MXSER_PORTS's tty_device is never registered and neither its
tty_port instance exists. Hence, it's quite pointless to allocate it.

It used to be used for global information fetches via ioctls. We have
just removed these as non-existent tty_device+tty_port was exactly the
reason to remove the ioctls.

It would be peculiar to add this "virtual" port as we require a backing
tty_port since commit ecbbfd44a08f (TTY: move tty buffers to tty_port)
in 2012.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-33-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 d354c80..007137c 100644 (file)
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1004,11 +1004,8 @@ static void mxser_shutdown_port(struct tty_port *port)
 static int mxser_open(struct tty_struct *tty, struct file *filp)
 {
        struct mxser_port *info;
-       int line;
+       int line = tty->index;
 
-       line = tty->index;
-       if (line == MXSER_PORTS)
-               return 0;
        info = &mxser_boards[line / MXSER_PORTS_PER_BOARD].ports[line % MXSER_PORTS_PER_BOARD];
        if (!info->ioaddr)
                return -ENODEV;
@@ -1077,7 +1074,7 @@ static void mxser_close(struct tty_struct *tty, struct file *filp)
        struct mxser_port *info = tty->driver_data;
        struct tty_port *port = &info->port;
 
-       if (tty->index == MXSER_PORTS || info == NULL)
+       if (info == NULL)
                return;
        if (tty_port_close_start(port, tty, filp) == 0)
                return;
@@ -1216,9 +1213,6 @@ static int mxser_get_serial_info(struct tty_struct *tty,
        struct tty_port *port = &info->port;
        unsigned int closing_wait, close_delay;
 
-       if (tty->index == MXSER_PORTS)
-               return -ENOTTY;
-
        mutex_lock(&port->mutex);
 
        close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
@@ -1249,8 +1243,6 @@ static int mxser_set_serial_info(struct tty_struct *tty,
        unsigned int flags, close_delay, closing_wait;
        int retval = 0;
 
-       if (tty->index == MXSER_PORTS)
-               return -ENOTTY;
        if (tty_io_error(tty))
                return -EIO;
 
@@ -1354,9 +1346,6 @@ static int mxser_tiocmget(struct tty_struct *tty)
        unsigned char control, status;
        unsigned long flags;
 
-
-       if (tty->index == MXSER_PORTS)
-               return -ENOIOCTLCMD;
        if (tty_io_error(tty))
                return -EIO;
 
@@ -1381,9 +1370,6 @@ static int mxser_tiocmset(struct tty_struct *tty,
        struct mxser_port *info = tty->driver_data;
        unsigned long flags;
 
-
-       if (tty->index == MXSER_PORTS)
-               return -ENOIOCTLCMD;
        if (tty_io_error(tty))
                return -EIO;
 
@@ -1433,9 +1419,6 @@ static int mxser_ioctl(struct tty_struct *tty,
        unsigned long flags;
        void __user *argp = (void __user *)arg;
 
-       if (tty->index == MXSER_PORTS)
-               return -ENOTTY;
-
        if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE) {
                int p;
                unsigned long opmode;
@@ -2211,7 +2194,7 @@ static int __init mxser_module_init(void)
 {
        int retval;
 
-       mxvar_sdriver = alloc_tty_driver(MXSER_PORTS + 1);
+       mxvar_sdriver = alloc_tty_driver(MXSER_PORTS);
        if (!mxvar_sdriver)
                return -ENOMEM;