2 files changed, 37 insertions, 4 deletions

diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index f2dfec82faf8..833e011a426f 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -509,6 +509,8 @@ static void io_serial_out(struct uart_port *p, int offset, int value)
         outb(value, p->iobase + offset);
 }
 
+static int serial8250_default_handle_irq(struct uart_port *port);
+
 static void set_io_from_upio(struct uart_port *p)
 {
         struct uart_8250_port *up =
@@ -557,6 +559,7 @@ static void set_io_from_upio(struct uart_port *p)
         }
         /* Remember loaded iotype */
         up->cur_iotype = p->iotype;
+        p->handle_irq = serial8250_default_handle_irq;
 }
 
 static void
@@ -1621,6 +1624,28 @@ static void serial8250_handle_port(struct uart_8250_port *up)
         spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
+{
+        struct uart_8250_port *up =
+                container_of(port, struct uart_8250_port, port);
+
+        if (!(iir & UART_IIR_NO_INT)) {
+                serial8250_handle_port(up);
+                return 1;
+        }
+
+        return 0;
+}
+
+static int serial8250_default_handle_irq(struct uart_port *port)
+{
+        struct uart_8250_port *up =
+                container_of(port, struct uart_8250_port, port);
+        unsigned int iir = serial_in(up, UART_IIR);
+
+        return serial8250_handle_irq(port, iir);
+}
+
 /*
  * This is the serial driver's interrupt routine.
  *
@@ -1648,13 +1673,12 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
         l = i->head;
         do {
                 struct uart_8250_port *up;
-                unsigned int iir;
+                struct uart_port *port;
 
                 up = list_entry(l, struct uart_8250_port, list);
+                port = &up->port;
 
-                iir = serial_in(up, UART_IIR);
-                if (!(iir & UART_IIR_NO_INT)) {
-                        serial8250_handle_port(up);
+                if (port->handle_irq(port)) {
 
                         handled = 1;
 
@@ -3048,6 +3072,10 @@ int __init early_serial_setup(struct uart_port *port)
                 p->serial_in = port->serial_in;
         if (port->serial_out)
                 p->serial_out = port->serial_out;
+        if (port->handle_irq)
+                p->handle_irq = port->handle_irq;
+        else
+                p->handle_irq = serial8250_default_handle_irq;
 
         return 0;
 }
@@ -3116,6 +3144,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
                 port.type               = p->type;
                 port.serial_in          = p->serial_in;
                 port.serial_out         = p->serial_out;
+                port.handle_irq         = p->handle_irq;
                 port.set_termios        = p->set_termios;
                 port.pm                 = p->pm;
                 port.dev                = &dev->dev;
@@ -3281,6 +3310,8 @@ int serial8250_register_port(struct uart_port *port)
                         uart->port.serial_in = port->serial_in;
                 if (port->serial_out)
                         uart->port.serial_out = port->serial_out;
+                if (port->handle_irq)
+                        uart->port.handle_irq = port->handle_irq;
                 /*  Possibly override set_termios call */
                 if (port->set_termios)
                         uart->port.set_termios = port->set_termios;
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 97f5b45bbc07..1f05bbeac01e 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -35,6 +35,7 @@ struct plat_serial8250_port {
         void            (*set_termios)(struct uart_port *,
                                        struct ktermios *new,
                                        struct ktermios *old);
+        int             (*handle_irq)(struct uart_port *);
         void            (*pm)(struct uart_port *, unsigned int state,
                               unsigned old);
 };
@@ -80,6 +81,7 @@ extern void serial8250_do_set_termios(struct uart_port *port,
                 struct ktermios *termios, struct ktermios *old);
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
                              unsigned int oldstate);
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 
 extern void serial8250_set_isa_configurator(void (*v)
                                         (int port, struct uart_port *up,