From: Bjorn Helgaas <bjorn.helgaas@hp.com>
Date: Thu, 15 Nov 2007 00:59:59 +0000 (-0800)
Subject: serial: only use PNP IRQ if it's valid
X-Git-Tag: v2.6.24-rc3~77
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e02f5f52cafbea013817d81f1acc4baf50d6324b;p=linux-2.6

serial: only use PNP IRQ if it's valid

"Luming Yu" <luming.yu@gmail.com> says:

  There is a "ttyS1 irq is -1" problem observed on tiger4 which cause the
  serial port broken.

  It is because that there is __no__ ACPI IRQ resource assigned for the
  serial port.  So the value of the IRQ for the port is never changed since it
  got initialized to -1.

If PNP supplies a valid IRQ, use it.  Otherwise, leave port.irq == 0, which
means "no IRQ" to the serial core.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yu Luming <luming.yu@intel.com>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/serial/8250_pnp.c b/drivers/serial/8250_pnp.c
index ad0755919b..1de098e754 100644
--- a/drivers/serial/8250_pnp.c
+++ b/drivers/serial/8250_pnp.c
@@ -439,7 +439,8 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	}
 
 	memset(&port, 0, sizeof(struct uart_port));
-	port.irq = pnp_irq(dev, 0);
+	if (pnp_irq_valid(dev, 0))
+		port.irq = pnp_irq(dev, 0);
 	if (pnp_port_valid(dev, 0)) {
 		port.iobase = pnp_port_start(dev, 0);
 		port.iotype = UPIO_PORT;