[argyllcms] Re: argyllcms 1.0.4 and libusb 1.0

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Tue, 03 Nov 2009 18:27:49 +1100

Frederic Crozat wrote:
Do you have plans to switch argyllcms to libusb 1.0 API, since it is
maintained and you are active on libusb mailing list ?

Not in the immediate future. The current version of libusb included
with Argyll works well with the instruments, whereas interfacing
to libusb 1.0 would need modifications and testing. For instance
there is a known problem with the i1pro Rev A. not working if there
is a delay between reading USB packets. The Argyll libusb takes care
of this by ping ponging between two buffers if more than one packet
is used. Switching to libusb 1.0 would therefore mean using the asynchronous
API, but because the libusb 1.0 API is not supported under MSWindows, this
creates a problem. (Note that upstream libusb 0.1 is refusing to accept any
patches, since they have moved on to 1.0). So at the moment there is no
compelling reason to spend time re-doing something that works, and
many reasons to spend the development time on other aspects of ArgyllCMS.
The main thing that would change this situation is if libusb 1.0 was
ported to MSWindows using both the existing libusb-win32 kernel driver
and winusb so that it would work on Vista/Windows 7 without needing signing.
[ As it is I'm tempted to hack a winusb driver into Argyll in a similar fashion
to the HID drivers, as the simplest way around this issue. ]

Graeme Gill.

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