1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c129a0e8e807..90621c3312bc 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1310,7 +1310,8 @@ static unsigned int check_modem_status(struct uart_8250_port *up)
 {
         unsigned int status = serial_in(up, UART_MSR);
 
-        if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI) {
+        if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
+            up->port.info != NULL) {
                 if (status & UART_MSR_TERI)
                         up->port.icount.rng++;
                 if (status & UART_MSR_DDSR)
@@ -1333,8 +1334,9 @@ static inline void
 serial8250_handle_port(struct uart_8250_port *up)
 {
         unsigned int status;
+        unsigned long flags;
 
-        spin_lock(&up->port.lock);
+        spin_lock_irqsave(&up->port.lock, flags);
 
         status = serial_inp(up, UART_LSR);
 
@@ -1346,7 +1348,7 @@ serial8250_handle_port(struct uart_8250_port *up)
         if (status & UART_LSR_THRE)
                 transmit_chars(up);
 
-        spin_unlock(&up->port.lock);
+        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 /*