Bug#501503: udev: Griffin Powermate USB knob doesn't get

Bug#501503: udev: Griffin Powermate USB knob doesn't get

[Marco d'Itri]

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Is this a good idea?

----- Forwarded message from Phil Endecott <spam_from_debian_bugs_7@chezphil.org> -----

From: Phil Endecott <spam_from_debian_bugs_7@chezphil.org>
To: Debian Bug Tracking System <submit@bugs.debian.org>
Subject: Bug#501503: udev: Griffin Powermate USB knob doesn't get
	/dev/input/by-id|path links
X-Mailer: reportbug 3.29.3

Package: udev
Version: 0.103-1
Severity: normal


Hi,

I have a Griffin Powermate, which is a USB "knob" that can be used as 
e.g. a volume control, for scrolling through video/audio, etc.  No
/dev/input/by-* links are created for it.  This is because
persistent-input.rules only sets ENV{ID_CLASS} for keyboards and mice
when it recognises them from their ATTRS{bInterfaceProtocol}.  This
device has ATTRS{bInterfaceProtocol}==0.  I have added this, to give
it class "misc"; I'm not sure if there is an official USB-spec-defined
meaning for protocol==0 that I should be using:

SUBSYSTEMS=="usb", \
        ATTRS{bInterfaceClass}=="03", ATTRS{bInterfaceProtocol}=="00", \
                                        ENV{ID_CLASS}="misc"
I now get the desired symlinks:

/dev/input/by-id/usb-Griffin_Technology,_Inc._Griffin_PowerMate-event-misc
/dev/input/by-path/pci-0000:00:10.2-usb-0:1:1.0-event-misc

Cheers,  Phil.

----- End forwarded message -----

-- 
ciao,
Marco

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Re: Bug#501503: udev: Griffin Powermate USB knob doesn't get

[Kay Sievers]

On Wed, Mar 18, 2009 at 10:48, Marco d'Itri <md@linux.it> wrote:
> From: Phil Endecott <spam_from_debian_bugs_7@chezphil.org>

> I have a Griffin Powermate, which is a USB "knob" that can be used as
> e.g. a volume control, for scrolling through video/audio, etc.  No
> /dev/input/by-* links are created for it.  This is because
> persistent-input.rules only sets ENV{ID_CLASS} for keyboards and mice
> when it recognises them from their ATTRS{bInterfaceProtocol}.  This
> device has ATTRS{bInterfaceProtocol}=0.  I have added this, to give
> it class "misc"; I'm not sure if there is an official USB-spec-defined
> meaning for protocol=0 that I should be using:
>
> SUBSYSTEMS="usb", \
>        ATTRS{bInterfaceClass}="03", ATTRS{bInterfaceProtocol}="00", \
>                                        ENV{ID_CLASS}="misc"
> I now get the desired symlinks:
>
> /dev/input/by-id/usb-Griffin_Technology,_Inc._Griffin_PowerMate-event-misc
> /dev/input/by-path/pci-0000:00:10.2-usb-0:1:1.0-event-misc

It's undefined if bInterfaceProtocol is 0.

What is the subclass value of the device? Like "lsusb -v" prints for a mouse:
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      1 Boot Interface Subclass
      bInterfaceProtocol      2 Mouse

Thanks,
Kay