[libhid-discuss] hid_force_open failed with return code 12

[Marius Scurtescu]

On 3/21/07, Charles Lepple <clepple at ghz.cc> wrote:
> On Mar 20, 2007, at 10:34 PM, Marius Scurtescu wrote:
>
> > Hi,
> >
> > I am using libhid under Ubuntu Edgy, tried both i386 and amd64
> > (0.2.15+20060325-2ubuntu1).
> >
> > Trying to access a Radio Shark 2 device. The problem is that libhid
> > cannot detach the kernel driver from the USB device.
> >
> > Using libhid-detach-device, same thing.
> >
> > Any suggestions?
>
> The most common problem is not having write permission to the device
> node in /dev/bus/usb/*/*.

That must be it. If I am running as root then it detaches fine. Only
root has write access to these devices. How can I change this? Should
I change the group or force write for all?

Also, the device gets created when you insert the USB connector, can
you control permissions on that?


>
> Is there any process that might have opened the device? If this might
> be the case, try 'lsof -n |grep hiddev' to see what it would be.

This is not the case.


>
> Also, what does 'cat /proc/bus/usb/devices' say about this device?

T:  Bus=02 Lev=01 Prnt=01 Port=08 Cnt=04 Dev#=  6 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=077d ProdID=627a Rev= 0.10
S:  Manufacturer=Griffin Technology, Inc.
S:  Product=radioSHARK
C:* #Ifs= 3 Cfg#= 1 Atr=80 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 0 Cls=01(audio) Sub=01 Prot=00 Driver=snd-usb-audio
I:  If#= 1 Alt= 0 #EPs= 0 Cls=01(audio) Sub=02 Prot=00 Driver=snd-usb-audio
I:  If#= 1 Alt= 1 #EPs= 1 Cls=01(audio) Sub=02 Prot=00 Driver=snd-usb-audio
E:  Ad=84(I) Atr=01(Isoc) MxPS=  50 Ivl=1ms
I:  If#= 1 Alt= 2 #EPs= 1 Cls=01(audio) Sub=02 Prot=00 Driver=snd-usb-audio
E:  Ad=84(I) Atr=01(Isoc) MxPS= 100 Ivl=1ms
I:  If#= 1 Alt= 3 #EPs= 1 Cls=01(audio) Sub=02 Prot=00 Driver=snd-usb-audio
E:  Ad=84(I) Atr=09(Isoc) MxPS= 200 Ivl=1ms
I:  If#= 2 Alt= 0 #EPs= 2 Cls=03(HID  ) Sub=00 Prot=00 Driver=usbhid
E:  Ad=83(I) Atr=03(Int.) MxPS=   7 Ivl=10ms
E:  Ad=05(O) Atr=03(Int.) MxPS=   7 Ivl=10ms


Thanks a lot,
Marius

>
> --
> Charles Lepple
>
>
>


-- 
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