Re: [linux-usb-devel] 2.6.20-rc4: usb somehow broken

From: Alan Stern
Date: Mon Jan 15 2007 - 11:03:52 EST


On Mon, 15 Jan 2007, Oliver Neukum wrote:

> Am Sonntag, 14. Januar 2007 20:47 schrieb icxcnika@xxxxxxxxxx:
> > > Can anyone suggest another approach?
> > >
> > > Alan Stern
> >
> > Just a thought, you could use both a blacklist approach, and a module
> > paramater, or something in sysfs, to allow specifying devices that won't
> > be suspend and resume compatible.
>
> Upon further thought, a module parameter won't do as the problem
> will arise without a driver loaded. A sysfs parameter turns the whole
> affair into a race condition. Will you set the guard parameter before the
> autosuspend logic strikes?
> Unfortunately this leaves only the least attractive solution.

There could be a mixed approach: a builtin blacklist that is extensible
via a procfs- or sysfs-based interface.

Note that we actually have two problems to contend with. Some devices
must never be autosuspended at all (they disconnect when resuming), and
others need a reset after resuming.

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/