[argyllcms] Re: Running dispcal stops usb card reader
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Wed, 15 Feb 2012 11:29:22 +1100
Juho Turunen wrote
> I have usb smartcard reader connected to my machine. When running
> dispcal the card reader stops working. Restarting the software which
> is using the card reader (VDR with softcam) gets the reader working
> again.
Hi,
looking into it, it seems that libusb attempts to open all the USB
devices it finds in order to determine their current configuration
and device descriptor. I'm not sure that this is a wise thing to do,
but that's what it does. Evidently this upsets usb-serial-driver/
smartcard reader.
So either it's a problem with libusb (and I doubt that there will
be any interest in them changing its behaviour, since the
API semantics depends on this information being available for
each device), or it's a bug in the usb-serial-driver in
being disturbed by such operations. Sorry, I don't think that
there is much I can do about either of these.
You're probably better off checking that this problem occurs if
you run the libusb lsusb utility, and then reporting it
on the libusb mailing list, and/or to those responsible
for the usb-serial-driver.
Graeme Gill.
Other related posts:
