4 files changed, 18 insertions, 11 deletions

diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index 63dd2c3ad95e..ae4836ea7442 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -115,7 +115,8 @@ static int __init add_legacy_soc_port(struct device_node *np,
 {
         u64 addr;
         const u32 *addrp;
-        upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;
+        upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
+                | UPF_FIXED_PORT;
         struct device_node *tsi = of_get_parent(np);
 
         /* We only support ports that have a clock frequency properly
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 09b0b736a751..336d0f4580d9 100644
--- a/drivers/serial/of_serial.c
+++ b/drivers/serial/of_serial.c
@@ -48,7 +48,8 @@ static int __devinit of_platform_serial_setup(struct of_device *ofdev,
         port->iotype = UPIO_MEM;
         port->type = type;
         port->uartclk = *clk;
-        port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+        port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
+                | UPF_FIXED_PORT;
         port->dev = &ofdev->dev;
         port->custom_divisor = *clk / (16 * (*spd));
 
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index a677133ab2d4..f409be37b62f 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -672,19 +672,21 @@ static int uart_set_info(struct uart_state *state,
          */
         mutex_lock(&state->mutex);
 
-        change_irq  = new_serial.irq != port->irq;
+        change_irq  = !(port->flags & UPF_FIXED_PORT)
+                && new_serial.irq != port->irq;
 
         /*
          * Since changing the 'type' of the port changes its resource
          * allocations, we should treat type changes the same as
          * IO port changes.
          */
-        change_port = new_port != port->iobase ||
-                      (unsigned long)new_serial.iomem_base != port->mapbase ||
-                      new_serial.hub6 != port->hub6 ||
-                      new_serial.io_type != port->iotype ||
-                      new_serial.iomem_reg_shift != port->regshift ||
-                      new_serial.type != port->type;
+        change_port = !(port->flags & UPF_FIXED_PORT)
+                && (new_port != port->iobase ||
+                    (unsigned long)new_serial.iomem_base != port->mapbase ||
+                    new_serial.hub6 != port->hub6 ||
+                    new_serial.io_type != port->iotype ||
+                    new_serial.iomem_reg_shift != port->regshift ||
+                    new_serial.type != port->type);
 
         old_flags = port->flags;
         new_flags = new_serial.flags;
@@ -796,8 +798,10 @@ static int uart_set_info(struct uart_state *state,
                 }
         }
 
-        port->irq              = new_serial.irq;
-        port->uartclk          = new_serial.baud_base * 16;
+        if (change_irq)
+                port->irq      = new_serial.irq;
+        if (!(port->flags & UPF_FIXED_PORT))
+                port->uartclk  = new_serial.baud_base * 16;
         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
                                  (new_flags & UPF_CHANGE_MASK);
         port->custom_divisor   = new_serial.custom_divisor;
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index d242c731491f..aadbfd30763f 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -263,6 +263,7 @@ struct uart_port {
 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 #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))
 #define UPF_IOREMAP             ((__force upf_t) (1 << 31))