>> > This indicates that the problem is a small hardware incompatibility, >>as I have said before. >> >>We attached a High Speed hub to our system and inserted this disk in the >>hub. The device works perfectly in such mode.
This is more than a small hardware problem. Assuming this HS hub was self powered, it indicates either your device took too much VBUS current, your host could not supply enough vbus power, your host transceiver has a problem, OR you have a major fussy device in receiving data. And even with this test info I have to assume that you used the same cable (a possible failure) between the good hub and the root hub. >> >>We also attached a Full speed hub (used in both bus and self powered >>mode) to our system and inserted this disk in the hub. The device fails >>to work in such mode. The reasons for device failure are identicle to >>case when it is directly connected to our system. What did your bus analyzer say in this case? Full speed is much more forgiving than high speed. I have seen a high speed mass storage device which would fail during enumeration in full speed (a small percentage of the time). HS is supposed to fall back to FS for all usb 2.0 devices, but it does seem that occasionally some devices are not 100% compliant :) >> >>The above experiments do not indicate hardware incompatibility. Do you >>agree ? >> Not in my opinion, this seems likes a major hardware problem somewhere. Regards, Steve ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
