Re: [PATCH] usb: gadget: f_rndis: fix usb_interface_descriptor for rndis

On 2014-09-24 20:12, Heiko Schocher wrote:

Hello Lars,

Am 24.09.2014 14:25, schrieb Lars Melin:

quoted

On 2014-09-24 13:48, Heiko Schocher wrote:

quoted

use the values for RNDIS over Ethernet as defined in
http://www.usb.org/developers/defined_class
(search for RDNIS):

- baseclass: 0xef (miscellaneous)
- subclass: 0x04
- protocol: 0x01

That is usb class, it is not the same thing as communication device 
class.

quoted

--- a/include/uapi/linux/usb/cdc.h
+++ b/include/uapi/linux/usb/cdc.h

@@ -12,6 +12,7 @@

#include <linux/types.h>
#define USB_CDC_SUBCLASS_ACM 0x02
+#define USB_CDC_SUBCLASS_RNDIS 0x04

No, no, no.
There is no CDC_SUBCLASS_RNDIS and you can not define one over an 
already used cdc subclass number, 0x04 is Multi-Channel Control Model

Ah, ok, so I have to define this values in a new header file, as there
is no current file for the USB_CLASS_MISC defines? Or is there a proper
place for them?

BTW: where do I find the "cdc subclass number, 0x04 is Multi-Channel
Control Model" define?

bye,
Heiko

You can still find the original specification usbcdc11.pdf on the net if 
you google for it, it has been pulled from usb.org where you could 
download it until a few years ago.
It is old but covers a lot of what you need to know.

Linux has afaik only the cdc.h definition file, everything else is coded 
by class/subclass in respectively drivers when needed.
02/02/ff  or  e0/01/03  are the most common interface attribute for 
rndis,  both of them together with a data interface with attributes 
0a/00/00.
Please check the whitelisting in drivers/net/usb/rndis_host.c  and also 
blacklistings in other net drivers under the same path, it should give 
you an idea how to bind an interface to a specific driver by interface 
attributes and/or usb vid:pid.
You should be able to do the same for your particular device.