Re: libusb broken on 2.6.28 x86_64 ?

[Mark Lord <lkml@rtr.ca>]

Mark Lord wrote:
> I'm trying to use 2.6.28 for the first time on an x86_64 box here
> with devices controlled by libusb.  The devices work on the first
> access, but then fail on all subsequent accesses.  Unplugging/replugging
> causes them to work again for a single subsequent access.
> 
> This is with two completely different USB gadgets:
> a VFD alphanumeric display, and an FTDI serial device in bitbang mode.
> 
> Did something break in 2.6.28 for libusb devices ??
..

Mmm.. broken only for 64-bit userspace, it seems.

I've recompiled the same app against 32-bit libs,
and it works just fine on that 64-bit system,
as well as on 32-bit systems.

But not when compiled for pure 64-bit operation on a 64-bit system.

Looks tricky .. must be a change somewhere that assumes
a pointer/long is 32-bits or something.

-ml