releases/3.8.4/tty-8250_pnp-serial-port-detection-regression-since-v3.7.patch

   1 From 77e372a3d82e5e4878ce1962207edd766773cc76 Mon Sep 17 00:00:00 2001
   2 From: Sean Young <sean@mess.org>
   3 Date: Fri, 22 Feb 2013 16:27:19 +0000
   4 Subject: tty/8250_pnp: serial port detection regression since v3.7
   5
   6 From: Sean Young <sean@mess.org>
   7
   8 commit 77e372a3d82e5e4878ce1962207edd766773cc76 upstream.
   9
  10 The InsydeH2O BIOS (version dated 09/12/2011) has the following in
  11 its pnp resouces for its serial ports:
  12
  13 $ cat /sys/bus/pnp/devices/00:0b/resources
  14 state = active
  15 io disabled
  16 irq disabled
  17
  18 We do not check if the resources are disabled, and create a bogus
  19 ttyS* device. Since commit 835d844d1a28e (8250_pnp: do pnp probe
  20 before legacy probe) we get a bogus ttyS0, which prevents the legacy
  21 probe from detecting it.
  22
  23 Note, the BIOS can also be upgraded, fixing this problem, but for people
  24 who can't do that, this fix is needed.
  25
  26 Reported-by: Vincent Deffontaines <vincent@gryzor.com>
  27 Tested-by: Vincent Deffontaines <vincent@gryzor.com>
  28 Signed-off-by: Sean Young <sean@mess.org>
  29 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  30
  31 ---
  32  drivers/tty/serial/8250/8250_pnp.c |   12 +++++++-----
  33  1 file changed, 7 insertions(+), 5 deletions(-)
  34
  35 --- a/drivers/tty/serial/8250/8250_pnp.c
  36 +++ b/drivers/tty/serial/8250/8250_pnp.c
  37 @@ -429,6 +429,7 @@ serial_pnp_probe(struct pnp_dev *dev, co
  38  {
  39         struct uart_8250_port uart;
  40         int ret, line, flags = dev_id->driver_data;
  41 +       struct resource *res = NULL;
  42
  43         if (flags & UNKNOWN_DEV) {
  44                 ret = serial_pnp_guess_board(dev);
  45 @@ -439,11 +440,12 @@ serial_pnp_probe(struct pnp_dev *dev, co
  46         memset(&uart, 0, sizeof(uart));
  47         if (pnp_irq_valid(dev, 0))
  48                 uart.port.irq = pnp_irq(dev, 0);
  49 -       if ((flags & CIR_PORT) && pnp_port_valid(dev, 2)) {
  50 -               uart.port.iobase = pnp_port_start(dev, 2);
  51 -               uart.port.iotype = UPIO_PORT;
  52 -       } else if (pnp_port_valid(dev, 0)) {
  53 -               uart.port.iobase = pnp_port_start(dev, 0);
  54 +       if ((flags & CIR_PORT) && pnp_port_valid(dev, 2))
  55 +               res = pnp_get_resource(dev, IORESOURCE_IO, 2);
  56 +       else if (pnp_port_valid(dev, 0))
  57 +               res = pnp_get_resource(dev, IORESOURCE_IO, 0);
  58 +       if (pnp_resource_enabled(res)) {
  59 +               uart.port.iobase = res->start;
  60                 uart.port.iotype = UPIO_PORT;
  61         } else if (pnp_mem_valid(dev, 0)) {
  62                 uart.port.mapbase = pnp_mem_start(dev, 0);