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

From: Alan Stern
Date: Wed Sep 28 2005 - 21:55:23 EST


On Thu, 29 Sep 2005, Daniel Ritz wrote:

> USB ohci controller having no handler. yenta shares the line, has the
> correct handler installer, sees the interrupt, does not handle it since
> it was not the cardbus bridge generating the interrupt but ohci.
> nobody cares about the interrupt, nobody tells the hardware to stop.
> hello interrupt storm. and during reesume...boom.

Does this occur during resume from disk? Most likely the controller was
enabled by the BIOS. Try passing the "usb-handoff" parameter to the boot
kernel when you resume.

> btw. i'm still suggesting not doing that free_irq() thing in suspend, at
> least not short-term. i was thinking that it is a good idea in the beginning,
> but Linus changed my mind...[ patch for usb ready ]

I think that calling free_irq during suspend is a good thing in general,
for the reason Adam Belay mentioned: It reduces interrupt overhead for
runtime power management, where a few devices may be suspended while the
rest of the system stays awake.

Of course, that doesn't mean I advocate going around right away and adding
those free_irq/request_irq pairs to every driver.

Alan Stern

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