[sane-devel] Timeouts: usb_reset seems necessary to avoid bulk timeouts.

[Tom Schutzer-Weissmann]

On Fri, 11 Jun 2004 13:50:39 +0900
Olaf Meeuwissen <olaf@epkowa.co.jp> wrote:

[...]

> Problem confirmed for the GT-9700 (aka Perfection 2450) with both the
> epson and epkowa backends.  Note that these same backends work fine
> with the GT-8200 (aka Perfection 1650) under identical conditions.
> 
> Just starting a SANE frontend (tried with xsane and iscan) with the
> GT-9700 already takes "ages" and it just refuses to preview.

Aha. That's not at all what I expected - many apologies to any slighted libusb developer!

Like I said, you can get it to work by calling usb_reset() whenever the scanner device is closed. My hacked code for sanei_usb_close() (in sanei/sanei_usb.c) is below.

I hope you don't need it :)

> Looks like Karl and/or I have some digging to do ;-(

Maybe. It would be very interesting to know what's wrong. Is it perhaps that the scanner needs to be send a message before it is closed.

Many thanks,
Tom

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void
sanei_usb_close (SANE_Int dn)
{
  DBG (5, "sanei_usb_close: closing device %d\n", dn);
  if (dn >= MAX_DEVICES || dn < 0)
    {

      DBG (1, "sanei_usb_close: dn >= MAX_DEVICES || dn < 0\n");
      return;
    }
  if (!devices[dn].open)
    {
      DBG (1, "sanei_usb_close: device %d already closed or never opened\n",
	   dn);
      return;
    }
  if (devices[dn].method == sanei_usb_method_scanner_driver)
    close (devices[dn].fd);
  else
#ifdef HAVE_LIBUSB
    {
#if 0
      /* Should only be done in case of a stall */
      usb_clear_halt (devices[dn].libusb_handle, devices[dn].bulk_in_ep);
      usb_clear_halt (devices[dn].libusb_handle, devices[dn].bulk_out_ep);
      /* be careful, we don't know if we are in DATA0 stage now */
      usb_resetep(devices[dn].libusb_handle, devices[dn].bulk_in_ep);
      usb_resetep(devices[dn].libusb_handle, devices[dn].bulk_out_ep);
#endif

/*	HACK FOR PERFECTION 2450  */
      usb_reset(devices[dn].libusb_handle) ;

      usb_release_interface (devices[dn].libusb_handle, 
			     devices[dn].interface_nr);
      usb_close (devices[dn].libusb_handle);
    }
#else
    DBG (1, "sanei_usb_close: libusb support missing\n");
#endif
  devices[dn].open = SANE_FALSE;
  return;
}

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