[sane-devel] Problem with libusb and 64 bits 2.6.25 kernel

[Nicolas]

Le mardi 27 mai 2008 à 15:42 -0400, m. allan noah a écrit :
> On Tue, May 27, 2008 at 3:29 PM, Nicolas <nicolas.martin at freesurf.fr> wrote:
> > Le lundi 26 mai 2008 à 19:12 -0400, m. allan noah a écrit :
> >> two random thoughts-
> >>
> >> 1. can he try 32 bit kernel on same exact machine, just to rule out
> >> hardware problems?
> >
> > Good point, and to try other USB ports on the same machine, that needs
> > to be confirmed first as it could be a HW issue
> >
> >> 2. is there a pattern to the timeouts, like always same number of
> >> errors before a good packet?
> >
> > It looks to be a repetitive pattern, i.e. error occurs on a second
> > "read" sequence when reading image data, but occurs also sometimes with
> > smaller transaction control messages (write message, then read response
> > immediately).
> > I've asked to give a try with a small tempo between two successive image
> > data readings, but do not have feedback yet.
> >
> > Thanks
> >
> 
> yes- it could be that his machine is too fast for the scanner, not
> that it is 64 bits.
> 
> allan

But this would mean that with machines getting faster and faster,
something needs to be adjusted, so that consecutive usb commands do not
occur within a too short delay. 

Unfortunately, I did not see any spec for such timings in libusb. 
Maybe something about that is the usb spec ? need to check this point...

Nicolas