On Sat, 29 Dec 2007 16:39:50 -0500, Yousuf Khan
wrote:

I have two generic 4-port USB hubs that are supposed to be USB 2.0
compliant. The older one is fine, works as advertised. Meanwhile the
newer one sometimes shows up under the USB 2.0 root hub (i.e. "Standard
Enhanced PCI to USB Host Controller"), or usually it shows up under the
slower "Standard OpenHCD USB Host Controller" (USB 1.1).

My motherboard (Asus M2NPV-VM) USB ports are all USB 2.0 compliant, and
they individually auto-detect whether they need to switch down to USB
1.1 speeds. I'm using a Microsoft tool called UVCView under Windows XP
to display the details of the USB devices, including the hubs and roothubs.

According to UVCView, the older hub and newer hub seem to have the same
chipset vendor (idVendor = "Genesys Logic, Inc."), although externally
they look quite different and have different brand names. So I'm not
sure why one would be consistently USB 2.0 compliant, while the other
one is not.

Now another interesting thing I noticed is that the inconsistent hub
will only show up as USB 2.0-compliant after I boot into Windows after
having previously rebooted from Ubuntu 7.10 Linux (dual-boot system). So
maybe Linux does something to the device that puts it right. But when I
list the devices while in Linux I see that it is listed under USB 1.1
just like when in Windows. I have no idea why Linux leaves the hub fixed
for Windows, but doesn't fix it for itself?!

Any idea what's going on with this hub?

Yousuf Khan

Crappy cable? I've seen a few times a 2.0 device gets downgraded to
1.x when connected with a substandard cable. A good quality cable
(try Belkin) solved it for me.
Oh, one more thought - check where the hub in question was made. If
it's China, that explains it. If they deliberately use led paint for
children's toys (saves a fraction of a penny per toy vs. non-toxic
one), and conveniently forget to put cord into tires (saves both
material and labor - a few bucks total per tire - who cares if people
die when it blows out), you can expect similar "quality" materials and
workmanship from the hub.

NNN