From 77e372a3d82e5e4878ce1962207edd766773cc76 Mon Sep 17 00:00:00 2001
From: Sean Young <sean@mess.org>
Date: Fri, 22 Feb 2013 16:27:19 +0000
Subject: tty/8250_pnp: serial port detection regression since v3.7

The InsydeH2O BIOS (version dated 09/12/2011) has the following in
its pnp resouces for its serial ports:

$ cat /sys/bus/pnp/devices/00:0b/resources
state = active
io disabled
irq disabled

We do not check if the resources are disabled, and create a bogus
ttyS* device. Since commit 835d844d1a28e (8250_pnp: do pnp probe
before legacy probe) we get a bogus ttyS0, which prevents the legacy
probe from detecting it.

Note, the BIOS can also be upgraded, fixing this problem, but for people
who can't do that, this fix is needed.

Reported-by: Vincent Deffontaines <vincent@gryzor.com>
Tested-by: Vincent Deffontaines <vincent@gryzor.com>
Signed-off-by: Sean Young <sean@mess.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/8250/8250_pnp.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

(limited to 'drivers')

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 35d9ab95c5cb..b3455a970a1d 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -429,6 +429,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
 	struct uart_8250_port uart;
 	int ret, line, flags = dev_id->driver_data;
+	struct resource *res = NULL;
 
 	if (flags & UNKNOWN_DEV) {
 		ret = serial_pnp_guess_board(dev);
@@ -439,11 +440,12 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	memset(&uart, 0, sizeof(uart));
 	if (pnp_irq_valid(dev, 0))
 		uart.port.irq = pnp_irq(dev, 0);
-	if ((flags & CIR_PORT) && pnp_port_valid(dev, 2)) {
-		uart.port.iobase = pnp_port_start(dev, 2);
-		uart.port.iotype = UPIO_PORT;
-	} else if (pnp_port_valid(dev, 0)) {
-		uart.port.iobase = pnp_port_start(dev, 0);
+	if ((flags & CIR_PORT) && pnp_port_valid(dev, 2))
+		res = pnp_get_resource(dev, IORESOURCE_IO, 2);
+	else if (pnp_port_valid(dev, 0))
+		res = pnp_get_resource(dev, IORESOURCE_IO, 0);
+	if (pnp_resource_enabled(res)) {
+		uart.port.iobase = res->start;
 		uart.port.iotype = UPIO_PORT;
 	} else if (pnp_mem_valid(dev, 0)) {
 		uart.port.mapbase = pnp_mem_start(dev, 0);
-- 
cgit v1.2.3-58-ga151