On Thu, 2 Jun 2005, Guennadi Liakhovetski wrote: > Hello > > On Wed, 1 Jun 2005, Alan Stern wrote: > > > On Mon, 30 May 2005, Guennadi Liakhovetski wrote: > > > > It sounds like there's some subtle incompatibility between the hub and > > your host controller. Beats me what it could be. Insufficient power? > > Same when I connect a power supply to the hub.
So that's not it... > > Does it make any different if you unload the ehci-hcd driver so everything > > runs only at full speed? > > Yes. Then it's ok. > > Another test I've performed - borrowed another 2.0 hub. First time I > plugged it in I was able to transfer the whole mem-stick (128MB) with dd > without an error! Then I discnnected it, reconnected the old one to verify > - errors. Reconnected the borrowed one - errors... Have I killed it too > now in this subtle inexplicable way?... Very unlikely. > All the same with a USB disk. > > A brief summary for David, in case he didn't follow this (added to CC): > > 2 PCs with VIA (UHCI companion) and ALi (OHCI) 2.0 cards, 1 high-speed > hub, high-speed mem-stick, card-reader and disk, full-speed bluetooth. > > All work connected directly to PCs. > > Work connected to hub, connected to VIA. > > High-speed not work connected to the hub on ALi with EHCI, but work with > OHCI only. Bluetooth works. > > I could borrow a USB-analyser, perhaps... If it would help. I can't think of anything else to try. It seems clear that this is a tricky low-level hardware incompatibility of some sort. It's not surprising that it only shows up at high speed, since high-speed transfers make much stronger demands on the hardware. There have been equally weird examples where high-speed devices wouldn't work when plugged directly into the PC but would work when attached through a hub. Apparently you've run across the converse sort of failure. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by Yahoo. Introducing Yahoo! Search Developer Network - Create apps using Yahoo! Search APIs Find out how you can build Yahoo! directly into your own Applications - visit http://developer.yahoo.net/?fr=offad-ysdn-ostg-q22005 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
