Re: hid device not claimed but /dev/input/event exists

From: Tomas Carnecky
Date: Tue Feb 19 2008 - 13:11:54 EST


Jiri Kosina wrote:
On Tue, 19 Feb 2008, Tomas Carnecky wrote:

The device apparently has four 'interfaces' - whatever that is, see [1]. It seems like usbhid probes interface 2 (which is the LCD plus a few buttons, probably the four just under the LCD, as described [1]). Because usbhid doesn't know how to handle the buttons, it fails. But then it probes interface 3 which is a 'proper' HID device with well-defined buttons.

Yes, the dump clearly shows that.

Does anything appear in dmesg when you press those buttons? There should be messages resembling the one you already have there:

drivers/hid/hid-core.c: report (size 8) (unnumbered)
drivers/hid/hid-core.c: report 0 (size 8) = 00 00 28 00 00 00 00 00

and they should react to keys such as FastForward, Play, Mute, Volume Up, etc.

Nothing. Not even after I removed the alsa-usb-audio driver. All I see is Keyboard.*, but the events from the speaker should be Key.*, right?

It looks like the speaker goes into a different mode once the USB cable is plugged in. Without the USB cable, the Z-10 acts as simple/dumb speaker, the volume up/down buttons change the internal volume, and I see that on the display, too. The play/next/prev song buttons don't do anything, which is quite obvious.
But once the USB cable is plugged in, the volume up/down buttons stop reacting. I assume they are now meant to send events to the computer so that some software can decide what to do. But features that are not useful for the computer (bass/treble), can still be controlled using the buttons on the speaker. The buttons are not dead. I can see that because the display goes to sleep after a few seconds of inactivity, and when I press the volume buttons, it wakes up and displays the current volume. So the speaker is definitely seeing that the buttons are being pressed.

Is there a USB packet inspector/dumper, like libpcap for network?

tom
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