1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 95c9f54f3d30..d2692d443f7b 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -1011,6 +1011,7 @@ static int mxser_open(struct tty_struct *tty, struct file *filp)
         if (!info->ioaddr)
                 return -ENODEV;
 
+        tty->driver_data = info;
         return tty_port_open(&info->port, tty, filp);
 }
 
@@ -1074,7 +1075,7 @@ 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)
+        if (tty->index == MXSER_PORTS || info == NULL)
                 return;
         if (tty_port_close_start(port, tty, filp) == 0)
                 return;
@@ -1768,7 +1769,7 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
                 int len, lsr;
 
                 len = mxser_chars_in_buffer(tty);
-                spin_lock(&info->slock);
+                spin_lock_irq(&info->slock);
                 lsr = inb(info->ioaddr + UART_LSR) & UART_LSR_THRE;
                 spin_unlock_irq(&info->slock);
                 len += (lsr ? 0 : 1);
@@ -1778,12 +1779,12 @@ static int mxser_ioctl(struct tty_struct *tty, struct file *file,
         case MOXA_ASPP_MON: {
                 int mcr, status;
 
-                spin_lock(&info->slock);
+                spin_lock_irq(&info->slock);
                 status = mxser_get_msr(info->ioaddr, 1, tty->index);
                 mxser_check_modem_status(tty, info, status);
 
                 mcr = inb(info->ioaddr + UART_MCR);
-                spin_unlock(&info->slock);
+                spin_unlock_irq(&info->slock);
 
                 if (mcr & MOXA_MUST_MCR_XON_FLAG)
                         info->mon_data.hold_reason &= ~NPPI_NOTIFY_XOFFHOLD;