Can not connect bus-powered USB hubs?
james at westexe.demon.co.uk
Sun Nov 14 22:18:13 UTC 2004
> I switched from RH8 to FC1 some time ago. After that my USB-camera, which is
> connected to the PC with 2 single-port extension cables, didn't work anymore.
> Versions FC2 and FC3-test3 (that I am running now) have the same problem.
> Is there a solution to this problem?
So is that
USB port <-- extension cable --><-- extension cable --><-- USB camera -->
USB port <-- ext. cable --><-- ext. cable --><--camera cable--><-- camera -->
How complex are those cables? How likely is it that there are chips in
What happens if you take them out of the equation?
> Here's some output that may be of any help:
> Nov 12 23:32:55 amdrvk kernel: usb 2-2.2: can't connect bus-powered hub to this port
This message comes from drivers/usb/core/hub.c. Above it is the comment:
/* consecutive bus-powered hubs aren't reliable; they can
* violate the voltage drop budget. if the new child has
* a "powered" LED, users should notice we didn't enable it
* (without reading syslog), even without per-port LEDs
* on the parent.
The kernel may have become more fussy about proper cabling because the
alternative may well be lost data.
Hope this helps,
E-mail address: james | ... File not found, I'll load something *I* think
@westexe.demon.co.uk | is interesting.
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