On Sunday 06 March 2005 9:28 am, Alan Stern wrote: > On Sun, 6 Mar 2005, Gerd v. Egidy wrote: > > > Switching the controller has helped! > > > > I bought an ALI as suggested. I still get a lot of usb resets but no > > disconnects anymore. This means the backup works without being > > killed but the overall speed is not good because of the time needed > > for the resets. > > This certainly supports the hypothesis that you're encountering hardware > errors at some level.
Yes. One person recently reported that the problems he saw with a Philips EHCI were fixed when his (custom) board switched the RC termination ... high speed signaling needs different values. I have a suspicion that some other boards have such signaling issues. Given that sort of issue, switching cables could matter too. Not all "old" cables are evidently capable of handling high speed signals. > > The guy at the shop said that he knows of a lot of disconnect problems with > > ALI and VIA controllers (but with windows of course). I'm not sure about that "of course"; there are more and more shops that have at least some Linux expertise. I like to encourage them. All it takes is one or two techies competent to reinstall a non-MSFT OS ... :) > > He suggests NEC > > controllers. Do you think a different controller might fix the resets or do > > you > > think the root cause for the resets is somewhere else (Cypress chip, driver > > issue,...) and the ALI controller just has a better handling for the resets? > > > If NEC - can I find out if the controller is EHCI 1.0 or 0.95 without > > plugging > > it in? Try different cables too. As a rule I'd expect it's not the controller, but the board it's installed on can matter a lot. Many boards are little more than re-labeled reference designs, and not all reference designs are particularly good. (Same issue applies on the peripheral side.) You can tell NEC 0.95 vs 1.0 by the part number, as I recall. 720100 being a 0.95 part, and I don't have a 1.0 version. The 0.95 is pretty solid under Linux. - Dave ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
