[sane-devel] sanei_usb_read_int function

Henning Meier-Geinitz henning@meier-geinitz.de
Tue, 30 Mar 2004 20:22:17 +0200


On Mon, Mar 29, 2004 at 07:30:12AM -0800, Peter Mark Guevarra wrote:
> Is sanei_usb_read_int function in SANEI related to implementing the
> handling of button press event of the scanner?

It's related to read the interrupt endpoints of an USB device. If your
scanner uses such an endpoint to announce button events that function
may help.

> Given that I already have the parameters, how can I use this function?

Like the bulk functions I think.

> When should I call this one?  Pardon me 'coz I'm quite new to
> interrupt handling...

I haven't looked into the details but I guess the problem is that
it'll wait for some data. And if the button hasn't been pressed it
will wait until the timeout (30 s).

So we'd need a function that doesn't block but I think libusb doesn't
provide that. We could also try a very low timeout.

Just try and tell us about the results :-)