USB Powered Speakers

Programmer In Training pit at joseph-a-nagy-jr.us
Fri Apr 9 13:07:35 UTC 2010


On 04/09/10 06:25, Warren Block wrote:
> On Fri, 9 Apr 2010, perryh at pluto.rain.com wrote:
> 
>> Programmer In Training <pit at joseph-a-nagy-jr.us> 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.

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