4 files changed, 17 insertions, 2 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 849af9d21feb..3ae497422db5 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2903,6 +2903,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
                 port.mapbase            = p->mapbase;
                 port.hub6               = p->hub6;
                 port.private_data       = p->private_data;
+                port.type               = p->type;
                 port.serial_in          = p->serial_in;
                 port.serial_out         = p->serial_out;
                 port.dev                = &dev->dev;
@@ -3058,6 +3059,14 @@ int serial8250_register_port(struct uart_port *port)
                 uart->port.private_data = port->private_data;
                 if (port->dev)
                         uart->port.dev = port->dev;
+
+                if (port->flags & UPF_FIXED_TYPE) {
+                        uart->port.type = port->type;
+                        uart->port.fifosize = uart_config[port->type].fifo_size;
+                        uart->capabilities = uart_config[port->type].flags;
+                        uart->tx_loadsz = uart_config[port->type].tx_loadsz;
+                }
+
                 set_io_from_upio(&uart->port);
                 /* Possibly override default I/O functions.  */
                 if (port->serial_in)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 9425ed69e0f7..dc68b7e0c930 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2179,11 +2179,14 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
          * Now do the auto configuration stuff.  Note that config_port
          * is expected to claim the resources and map the port for us.
          */
-        flags = UART_CONFIG_TYPE;
+        flags = 0;
         if (port->flags & UPF_AUTO_IRQ)
                 flags |= UART_CONFIG_IRQ;
         if (port->flags & UPF_BOOT_AUTOCONF) {
-                port->type = PORT_UNKNOWN;
+                if (!(port->flags & UPF_FIXED_TYPE)) {
+                        port->type = PORT_UNKNOWN;
+                        flags |= UART_CONFIG_TYPE;
+                }
                 port->ops->config_port(port, flags);
         }
 
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 77d83d929f2c..d4d2a78ad43e 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -28,6 +28,7 @@ struct plat_serial8250_port {
         unsigned char   iotype;         /* UPIO_* */
         unsigned char   hub6;
         upf_t           flags;          /* UPF_* flags */
+        unsigned int    type;           /* If UPF_FIXED_TYPE */
         unsigned int    (*serial_in)(struct uart_port *, int);
         void            (*serial_out)(struct uart_port *, int, int);
 };
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 60061f44f3d8..f155252f148c 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -295,6 +295,8 @@ struct uart_port {
 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
+/* The exact UART type is known and should not be probed.  */
+#define UPF_FIXED_TYPE          ((__force upf_t) (1 << 27))
 #define UPF_BOOT_AUTOCONF       ((__force upf_t) (1 << 28))
 #define UPF_FIXED_PORT          ((__force upf_t) (1 << 29))
 #define UPF_DEAD                ((__force upf_t) (1 << 30))