Re: [linux-usb-devel] Re: 2.6.13-mm2

Alan Stern
2005-09-28T21:10:44Z

On Wed, 28 Sep 2005, Daniel Ritz wrote:

> > It's handled in hcd-pci.c ... All PCI based HCDs release their IRQs
> > when they suspend. Including OHCI. Your diagnosis is incorrect.
>
> would you be kind enough to tell me where?
>
> my point is: the test patch i sent to rafael which comments out the
> free_irq-on-suspend thing in hcd-pci.c shows that something is wrong with
> USB (i think only OHCI. UHCI looks ok and about EHCI i have no data).

There are two issues here: freeing the IRQ handler and preventing the
device from generating interrupt requests in the first place. Dave and I
discussed this some time ago and agreed it was vital to stop interrupt
generation at the source, before releasing the handler, whenever the
device is suspended.

So the real question becomes, is your OHCI controller somehow generating
interrupt requests at a time when it shouldn't be? Adding debugging
printk's to the driver's interrupt handler could answer this.

If it isn't, then the problem you see has some other cause. ACPI often
turns out to be the culprit.

Alan Stern