serial: only use PNP IRQ if it's valid

"Luming Yu" <[email protected]> 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 <[email protected]>
Cc: Yu Luming <[email protected]>
Acked-by: Matthew Wilcox <[email protected]>
Cc: Alan Cox <[email protected]>
Cc: Russell King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions