[linux-usb-devel] [PATCH 1/5] USB: Make usb_hcd_irq work for multi-role USB controllers w/ shared irq

[Alan Cox]

On Fri, 23 Nov 2007 21:10:39 -0800
Greg KH <gregkh at suse.de> wrote:

> On Fri, Nov 23, 2007 at 05:24:31PM -0700, Grant Likely wrote:
> > From: Peter Korsgaard <peter.korsgaard at barco.com>
> > 
> > Some multi-role (host/peripheral) USB controllers use a shared interrupt
> > line for all parts of the chip. Export usb_hcd_irq so drivers can call it
> > from their interrupt handler instead of duplicating code.
> > Drivers pass an irqnum of 0 to usb_add_hcd to signal that the interrupt handler
> > shouldn't be registerred by the core.
> 
> What about for platforms where irq 0 is a valid irq?

There are no such platforms. Linus made that absolutely clear every time
this came up before

	0	-	No IRQ

A platform with a physical or bus IRQ of 0 needs to remap it to a
different constant.

Alan