Re: ThinkPad T41 - Strange USB 2.0 behaviour

From: Jiri Kosina
Date: Fri Jun 08 2007 - 06:18:22 EST


linux-usb-devel list added

On Fri, 8 Jun 2007, Robert de Rooy wrote:

> Jiri Kosina wrote:
> > On Thu, 7 Jun 2007, Robert de Rooy wrote:
> >
> >
> > > Yes I figured it was a hardware problem, but that was not really the point
> > > I was trying to raise ;). I would like, if possible for Linux to
> > > automatically fallback to USB 1.1 like Windows does (preferably with a
> > > suitable warning).
> > >
> >
> > What do you propose as a trigger for the kernel to fallback?
> >
> > You can work it around manually, just don't use ehci-hcd, can't you?
> >
> >
> Yes I can unload ehci-hcd, but I have one USB 2.0 device that strangely enough
> DOES work as such, and unloading ehci-hcd will cause that also to run at 1.1
> speed.
>
> Clearly something is failing when plugging a device with ehci-hcd loaded, the
> driver seems to keep retrying indefinitely. Instead it would be nice if after
> a few tries it hands the device over to uhci-hcd. This seems to be the
> behaviour under Windows, so I was wondering if Linux could be made to do
> something similar.
>
>

--
Jiri Kosina
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