Clemens Ladisch <clemens-P6GI/4k7KOmELgA04lAiVw(a)public.gmane.org>
writes:
David Kastrup wrote:
I just got some older Bamster soundbar model
(probably not a keeper)
that takes USB either for power (in which case it uses AUX in analog) or
also as USB soundcard. In the latter case, however, it just switches
itself off after a few seconds.
[ 1201.960192] usb 5-2: new full-speed USB device number 5 using uhci_hcd
[ 1203.344305] usbhid 5-2:1.3: can't add hid device: -71
[ 1203.456336] usb 5-2: USB disconnect, device number 5
I'd guess that the firmware tries to detect if it is connect to an actaual
PC (as opposed to some charger), and that Linux doesn't look right.
It doesn't have batteries to charge. If I plug in the AUX cord, I can
switch it on and it stays on (without attempting to announce it on USB).
You sure that it's the Bamster taking the initiative here? If I wait
for just the right moment, I can see in cat /etc/asound/cards
dak@lola:/usr/local/tmp/lilypond$ cat /proc/asound/cards
0 [Intel ]: HDA-Intel - HDA Intel
HDA Intel at 0xfe020000 irq 29
1 [Audio ]: USB-Audio - USB Audio
ACTIONS USB Audio at usb-0000:00:1d.0-2, full speed
immediately before it switches itself off again.
This behavior just does not make sense. I cannot rule out that the
chipset might be used in devices where this would be part of more useful
behavior but with as little clue as I have it sounds more like Linux
does something bad here. Should it respond differently to any request?
--
David Kastrup