Re: USB Powered Speakers



On 04/09/10 06:25, Warren Block wrote:
On Fri, 9 Apr 2010, perryh@xxxxxxxxxxxxxx wrote:

Programmer In Training <pit@xxxxxxxxxxxxxxxxxxx> wrote:

... they are only attached for power purposes ...

Input power: DC 5V 500mA

Any chance these speakers need a USB 2.0 port, and all the ports
on your FreeBSD box are 1.x? I don't remember the USB power spec
offhand, but 2.5W may exceed what a USB 1.x port can supply --
a limit that applies regardless of the system's overall power
provisioning.

500 mA is 5 unit loads for USB 2.0, or powered hub territory. The
device has to request that high power mode, and the system can say no
and disable the port. That should show in /var/log/messages.
<snip>

The following messages so far haven't shown up today.

Apr 8 22:30:01 heaven root: Unknown USB device: vendor 0x046e product
0x5542 bus uhub4
Apr 8 22:30:01 heaven kernel: uhid0: <vendor 0x046e product 0x5542,
class 0/0, rev 1.10/1.10, addr 3> on usbus4
Apr 8 22:30:01 heaven kernel: uhub_explore:611: illegal enable change,
port 3
Apr 8 22:30:15 heaven kernel: ugen4.3: <vendor 0x046e> at usbus4
(disconnected)
Apr 8 22:30:15 heaven kernel: ukbd0: at uhub4, port 3, addr 3
(disconnected)
Apr 8 22:30:15 heaven kernel: uhid0: at uhub4, port 3, addr 3
(disconnected)
Apr 8 22:30:16 heaven kernel: usb_alloc_device:1586: set address 3
failed (USB_ERR_IOERROR, ignored)
Apr 8 22:30:16 heaven kernel: usb_alloc_device:1624: getting device
descriptor at addr 3 failed, USB_ERR_IOERROR!


--
Yours In Christ,

PIT
Emails are not formal business letters, whatever businesses may want.
Original content copyright under the OWL http://owl.apotheon.org
Please do not CC me. If I'm posting to a list it is because I am subscribed.

Attachment: signature.asc
Description: OpenPGP digital signature



Relevant Pages