Le mardi 27 mai 2008 ? 15:42 -0400, m. allan noah a ?crit : > On Tue, May 27, 2008 at 3:29 PM, Nicolas <nicolas.martin at freesurf.fr> > wrote: > > Le lundi 26 mai 2008 ? 19:12 -0400, m. allan noah a ?crit : > >> 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
