Red Hat Bugzilla – Bug 144253
Griffin Powermate does not work, not allocated event device
Last modified: 2015-01-04 17:14:51 EST
Description of problem: The Griffin Powermate does not work in FC3 (tested with kernels 2.6.9-1.681_FC3, 2.6.9-1.724_FC3, 2.6.10-1.727_FC3) It should be allocated a device node under /dev/input but according to the kernel messages it is allocated a NULL device. Jan 4 12:29:09 castor kernel: usb 1-6.3: new low speed USB device using address 14 Jan 4 12:29:09 castor kernel: usbhid: probe of 1-6.3:1.0 failed with error -5 Jan 4 12:29:09 castor hal.hotplug[1469]: DEVPATH is not set Jan 4 12:29:09 castor kernel: input: Griffin PowerMate on <NULL> Steps to Reproduce: 1. Plug in Griffin Powermate Actual Results: 1. Not detected correctly by the kernel. Expected Results: 1. Allocated dev node and available for configuration in X etc. using something like evrouter. This worked in FC1 / kernel 2.4.x
I tried the fix in #91677 but no effect, log messages exactly as before. I also note that the evdev module does not appear to be present on my system, but evdev.h is under /lib/modules/`uname -r`/build/include/config/input/evdev.h so I assume it is compiled into the kernel.
I wonder if this is something to do with udev or hotplug? I notice that /dev/input/event2 is touched whenever I plugin the device, but the log message always indicates <NULL> device allocated.
I'm not sure whether I am on the right track here as I've never really had to do kernel debugging before. I believe the -5 is -EIO being returned from powermate_probe in drivers/usb/input/powermate.c Unfortunately there are 3 conditions on which this might be returned and at this point the code gets beyond my level of understanding so I am not sure which is the case. It is also not clear to me whether the -5 error is anything to do with the reason that the <NULL> device is allocated when the PowerMate is plugged in.
OK more information on this bug... Running the userspace tools from http://www.graflex.org/klotz/software/griffin/ things now "kind of" work. The rotomatic utility (reads rotation events) works as my normal user. The brighten and pulseled utilities fail and report that I don't have permission to open /dev/input/event2 (it works as root). They are looking for write access so this makes some sense. I will try configuring the device for use with the Gimp later.
OK I have now found an excellent resource allowing me to get the PowerMate working in Linux: http://gentoo-wiki.com/HOWTO_Griffin_PowerMate_with_UDEV_and_Kernel_2.6.x This details some udev and hotplug changes which need to be made to set the permissions correctly (so I'm switching this from a kernel to a udev bug for now). However it does not resolve the existing problem where the kernel reports a <NULL> event device has been allocated.
no bug in my opinion.. this is a normal user configuration. And no, I will not start to build up a product database... sry, this does not belong in the standard udev-package. Everything (but /etc/security/console.perms) could be packed in config files together in a seperate rpm (PowerMate-0.1.noarch.rpm)