[libhid-discuss] LIBHID: Latest SVN Trunk: hid_opening.c: hid_compare_usb_device(): product_id matched incorrectly

[Christopher Becker]

That's too funny.  You guessed by the product ID I suppose :).  Thanks for
rewriting that.  I will definitely have a look.  Are the command line
options the same or is everything different?


~ Chris

On Sun, Apr 19, 2015 at 10:34 PM, Andrew Silverman <andrewsi at microsoft.com>
wrote:

>  If you're trying to rewrite the Linux tools for the ultimarc u360, I've
> already done it- posted on github under andrewsil1/ultrastik tools.
>
> _____________
> Andy
>
>
>
>
> On Sun, Apr 19, 2015 at 9:15 PM -0700, "christopher.alan.becker at gmail.com"
> <christopher.alan.becker at gmail.com> wrote:
>
>   Thanks Andrew and Charles for the responses.
>
> @Andrew: At least now I know I'm not crazy :)
>
> I'm working with a USB driver for a joystick that uses libhid. If I ever
> have to rewrite it, I will definitely go down the HIDAPI route.
>
> Much appreciated!
>
>
> ~ Chris
>
> On 4/19/2015 9:18 PM, Andrew Silverman wrote:
> > My recollection is that this is already a known bug that was never
> officially patched, as evidently libhid has long since been considered
> obsolete in favor of newer HID libraries (
> http://www.signal11.us/oss/hidapi/).  I have the same change in my own
> code that still works with the existing library.
> >
> > -----Original Message-----
> > From: libhid-discuss [
> mailto:libhid-discuss-bounces+andrewsi=microsoft.com at lists.alioth.debian.org
> <libhid-discuss-bounces+andrewsi=microsoft.com at lists.alioth.debian.org>]
> On Behalf Of christopher.alan.becker at gmail.com
> > Sent: Sunday, April 19, 2015 7:15 PM
> > To: libhid-discuss at lists.alioth.debian.org
> > Subject: [libhid-discuss] LIBHID: Latest SVN Trunk: hid_opening.c:
> hid_compare_usb_device(): product_id matched incorrectly
> >
> > Hi:
> >
> > I ran into a situation with libhid where a USB product  ID of 0x0501 was
> matching on a USB device with a product ID of 0x0503.  I narrowed it down
> in hid_compare_usb_device() to the line below:
> > -----
> > ((dev->descriptor.idProduct & match->product_id) == match->product_id)
> > -----
> >
> > Tracing the values of the above, both match and dev descriptor, the
> values were showing correct (0x0501, 0x0503), but still evaluating as
> matched.
> >
> > If I change the above code to just:
> > -----
> > (dev->descriptor.idProduct == match->product_id)
> > -----
> >
> > Then the product ID's match correctly, and only 0x0501 matches 0x0501.
> > Any ideas on why 0x0503 would match 0x0501 on the original code?
> >
> > Actual hex codes were set/used in the passed HIDInterfaceMatcher struct.
> >
> > As a side note, the vendor ID did not experience this problem. Latest
> SVN trunk (2015-04-19).
> >
> > Thanks.
> >
> >
> > ~ Chris
> >
> > _______________________________________________
> > libhid-discuss mailing list
> > libhid-discuss at lists.alioth.debian.org
> > http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/libhid-discuss
> > http://libhid.alioth.debian.org/
>
>
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