27 Jan
2014
27 Jan
'14
11:03 a.m.
On Mon, 27 Jan 2014 10:05:20 +0100, Andre Majorel wrote
On 2014-01-26 22:55 +0100, Andre Majorel wrote:
[...]
Is that a USB-1 or a USB-2 device? 5 meters are way above
the USB-1 Specs (3m max.).
Tried the Romio II with itself again : it failed
as before.
Found a large number of "usb_submit_urb: -22" messages in
kern.log for yesterday (but none for today).
If the Romio II is connected directly to the computer, instead
of through a USB hub at the end of a 5-m cable, alsa-midi-latency-test -o 24:0 -i 24:1
works fine.
What are you supposed to do in a case like this ? Get a better
hub ? Get a better MIDI interface ? Work around the problem in
software ? What a mess !
There are some devices that refuse to work with a hub (no matter
how short the cable is). My -m-Audio Axiom 61 refuses to connect
via a hub - a fact mentioned in the fine manual but _not_ in any
promotional material :-(
I think this is either a bug in their Usb chip firmware or some
engineer tried to be oversmart (i.e. hubs might introduce latency/jitter
hence we won't work with hubs).
HTH Ralf Mattes
It is a 7-port powered USB hub (Heden HUBUSB7PCB /
HUBUSB7PCW).
--
André Majorel http://www.teaser.fr/~amajorel/
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--
R. Mattes -
Hochschule fuer Musik Freiburg
rm(a)inm.mh-freiburg.de