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 ad07559..1de098e 100644
--- a/drivers/serial/8250_pnp.c
+++ b/drivers/serial/8250_pnp.c
@@ -439,7 +439,8 @@
}
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;
