[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Pine.LNX.4.44L0.0812051100560.2588-100000@iolanthe.rowland.org>
Date: Fri, 5 Dec 2008 11:03:41 -0500 (EST)
From: Alan Stern <stern@...land.harvard.edu>
To: Marc Haber <mh+linux-kernel@...schlus.de>
cc: Greg KH <greg@...ah.com>,
Andrew Morton <akpm@...ux-foundation.org>,
<linux-kernel@...r.kernel.org>, <linux-usb@...r.kernel.org>
Subject: Re: pl2303 - pl2303_open - failed submitting interrupt urb, error
-28
On Fri, 5 Dec 2008, Marc Haber wrote:
> On Wed, Dec 03, 2008 at 07:47:25AM -0800, Greg KH wrote:
> > I would suggest using a USB 1.1 hub instead if you have to use this kind
> > of hardware set up.
>
> It is nearly impossible to buy that kind of hardware at the current
> time.
>
> > I think the core is just not able to schedule so many interrupt urbs
> > with such a setup, running USB 1.1 devices behind a USB 2.0 hub like
> > this is a very difficult thing to do.
> >
> > Sorry I don't have a better solution.
>
> Is it possible to disable USB 2.0 for selected links?
Yes it is. You can force port P of the EHCI controller on bus B to run
at low/full speed by doing:
echo P >/sys/class/usb_host/usb_hostB/companion
To allow port P to run at high speed again, use the same command but
write -P instead of P.
Alan Stern
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists