[sane-devel] Problems with libusb and Snapscan 1236U (maybe similar to others): USB dump
m. allan noah
anoah at pfeiffer.edu
Mon Mar 1 17:44:26 GMT 2004
reset is the past tense of reset, since you asked. (dont ask, its
english).
is there any way for a backend to tell what the current status of the
toggle is, before closing the connection?
allan
On Mon, 1 Mar 2004, Henning Meier-Geinitz wrote:
> Hi,
>
> On Mon, Mar 01, 2004 at 11:46:58AM -0500, m. allan noah wrote:
> > if that works, then perhaps there is a libusb/linux kernel error that
> > prevents the DATA0/1 toggle from frobbing.
>
> IIRC that's a bug in some USB chipsets. It happens when the connection
> is resetted (?). The USB spec says that in this case the toggle should
> be set to 0. Linux does that but some USB chips (e.g. Mustek 1017)
> doesn't. So everytime the connection is reset with toggle = data1 the
> communication fails. With libusb this happens after every close. With
> the kernel scanner driver only when the module is unloaded. On *BSD
> it also happens with every close().
>
> So it may not be a bug in the kernel.
>
> Bye,
> Henning
>
>
--
"so don't tell us it can't be done, putting down what you don't know.
money isn't our god, integrity will free our souls" - Max Cavalera
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