Re: [libusb] libusb_open returns -12 (LIBUSB_ERROR_NOT_SUPPORTED)

[Robert R. <R.R...@Qu...>]

Hi Matthias,
I wish to apologize for a misstatement I made.  See below

At 11:18 AM 9/22/2021 +0200, Matthias Bolte wrote:
>Am Mi., 22. Sept. 2021 um 03:38 Uhr schrieb Xiaofan Chen <xia...@gm...>:
> >
> > On Wed, Sep 22, 2021 at 7:37 AM Robert Ritchey
> > <R.R...@qu...> wrote:
> > >
>
>A few things to check:
>
>- Why are you only checking the vendor ID before opening the device?
>You should check the product ID too to avoid trying to open the wrong
>device.

You are right, I do not check the Product ID before opening.

I guess since this is my Vendor ID and I intend to use this for a number
of devices (which device is checked elsewhere in the code) I did not see a
reason to restrict the USB code to look for specific Product IDs.  My
products range with an ID of 1 - 127 and the test fixtures are numbered
from 128 - 255.  I guess I could check this range but why would another
device have my Vendor ID and if it did, they could have a Product ID in
the range of 1 -255 anyway.

thanks,

-Bob
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Robert Ritchey
Quest Engineering & Development, Inc.
Suite B-8
6125 South Ash Avenue
Tempe, AZ 85283
Tel: (480) 460-2652
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