Re: [Libusb-devel] I need the SerialNumber for a plain linux-use r

[Charles L. <cl...@gm...>]

On 9/26/05, Chen Xiao Fan <xi...@sg...> wrote:
> So the question is how to set the correct permission of
> /proc/bus/usb without modifying it in /etc/fstab.

That's where the hotplug scripts come in to play. You would write a
script that sets the group of the /proc/bus/usb/<bus>/<dev> node to
pickit (or whatever), and chmod g+w.

> T:  Bus=3D02 Lev=3D01 Prnt=3D01 Port=3D01 Cnt=3D01 Dev#=3D 14 Spd=3D12  M=
xCh=3D 0
> D:  Ver=3D 2.00 Cls=3D00(>ifc ) Sub=3D00 Prot=3D00 MxPS=3D 8 #Cfgs=3D  2
> P:  Vendor=3D04d8 ProdID=3D0033 Rev=3D 0.01
> S:  Manufacturer=3DMicrochip Technology Inc.
> S:  Product=3DPICkit 2 Microcontroller Programmer
> S:  SerialNumber=3DPIC18F2550

The following is the first configuration:

> C:* #Ifs=3D 1 Cfg#=3D 1 Atr=3D80 MxPwr=3D100mA
> I:  If#=3D 0 Alt=3D 0 #EPs=3D 2 Cls=3D03(HID  ) Sub=3D00 Prot=3D00 Driver=
=3Dusbhid
> E:  Ad=3D81(I) Atr=3D03(Int.) MxPS=3D  64 Ivl=3D1ms
> E:  Ad=3D01(O) Atr=3D03(Int.) MxPS=3D  64 Ivl=3D1ms

And this is the 2nd config:

> C:  #Ifs=3D 1 Cfg#=3D 2 Atr=3D80 MxPwr=3D100mA
> I:  If#=3D 0 Alt=3D 0 #EPs=3D 2 Cls=3Dff(vend.) Sub=3D00 Prot=3D00 Driver=
=3D
> E:  Ad=3D81(I) Atr=3D03(Int.) MxPS=3D  64 Ivl=3D1ms
> E:  Ad=3D01(O) Atr=3D03(Int.) MxPS=3D  64 Ivl=3D1ms

Note how both specify EP1IN (Ad=3D81) and EP1OUT (Ad=3D01). That is why I
mentioned that they are mutually exclusive - you do not want the
kernel claiming interface 1 on config 1 while your application tries
to claim interface 1 on config 2.

If I understand correctly, you should detach the kernel driver first
before setting the configuration (otherwise the kernel is still
claiming interface 1/config 1). After that, you should claim the
interface with libusb.

Same deal on the PICkit 1:

> T:  Bus=3D01 Lev=3D01 Prnt=3D01 Port=3D02 Cnt=3D01 Dev#=3D  2 Spd=3D1.5 M=
xCh=3D 0
> D:  Ver=3D 1.10 Cls=3D00(>ifc ) Sub=3D00 Prot=3D00 MxPS=3D 8 #Cfgs=3D  2
> P:  Vendor=3D04d8 ProdID=3D0032 Rev=3D 0.00
> S:  Manufacturer=3DMicrochip Technology Inc.
> S:  Product=3DPICkit(TM) 1 FLASH Starter Kit
> C:* #Ifs=3D 1 Cfg#=3D 1 Atr=3D80 MxPwr=3D100mA
> I:  If#=3D 0 Alt=3D 0 #EPs=3D 2 Cls=3D03(HID  ) Sub=3D00 Prot=3D00 Driver=
=3Dusbhid
> E:  Ad=3D81(I) Atr=3D03(Int.) MxPS=3D   8 Ivl=3D10ms
> E:  Ad=3D01(O) Atr=3D03(Int.) MxPS=3D   8 Ivl=3D10ms
> C:  #Ifs=3D 1 Cfg#=3D 2 Atr=3D80 MxPwr=3D100mA
> I:  If#=3D 0 Alt=3D 0 #EPs=3D 2 Cls=3Dff(vend.) Sub=3D00 Prot=3D00 Driver=
=3D
> E:  Ad=3D81(I) Atr=3D03(Int.) MxPS=3D   8 Ivl=3D10ms
> E:  Ad=3D01(O) Atr=3D03(Int.) MxPS=3D   8 Ivl=3D10ms

[...]

> usb 1-3: configuration #1 chosen from 2 choices
> hiddev97: USB HID v1.00 Device [Microchip Technology Inc. PICkit(TM) 1 FL=
ASH
> Starter Kit] on usb-0000:00:02.0-3
> usb 2-2: usbfs: interface 0 claimed while 'pk2' sets config #2

the last line is telling you that interface 0 is still claimed by the
kernel when you set config #2. See above.

--
- Charles Lepple