serial: fix device name reporting when minor space is shared between drivers

The multiple drivers share the minor space occupied by a particular major
number, the actual index within the device name's space is indicated by
the tty_driver->name_base + uart_port->line

Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line

Use those to print the device names properly in such situations in
serial_core.c and 8250.c

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 308588e2072..6bdf3362e3b 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2051,7 +2051,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
                                         "transmitter\n",
                                port->dev ? port->dev->bus_id : "",
                                port->dev ? ": " : "",
-                               drv->dev_name, port->line);
+                               drv->dev_name,
+                               drv->tty_driver->name_base + port->line);
 
                 ops->shutdown(port);
         }
@@ -2176,7 +2177,9 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
                port->dev ? port->dev->bus_id : "",
                port->dev ? ": " : "",
-               drv->dev_name, port->line, address, port->irq, uart_type(port));
+               drv->dev_name,
+               drv->tty_driver->name_base + port->line,
+               address, port->irq, uart_type(port));
 }
 
 static void