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

From: Heiko Schocher
Date: Wed Sep 24 2014 - 09:12:26 EST

Hello Michal,

Am 24.09.2014 11:38, schrieb Michal Nazarewicz:
On Wed, Sep 24 2014, Heiko Schocher<hs@xxxxxxx> wrote:
use the values for RNDIS over Ethernet as defined in
(search for RDNIS):

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

with this setings the file in Documentation/usb/linux.inf is

Signed-off-by: Heiko Schocher<hs@xxxxxxx>


Cc: Felipe Balbi<balbi@xxxxxx>
Cc: Greg Kroah-Hartman<gregkh@xxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Oliver Neukum<oliver@xxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-api@xxxxxxxxxxxxxxx
Cc: Andrzej Pietrasiewicz<andrzej.p@xxxxxxxxxxx>
Cc: Michal Nazarewicz<mina86@xxxxxxxxxx>
Cc: Kyungmin Park<kyungmin.park@xxxxxxxxxxx>
Cc: Dan Carpenter<dan.carpenter@xxxxxxxxxx>
Cc: Macpaul Lin<macpaul@xxxxxxxxx>

Tested with the "USB Compliance test suite which runs Windows", see:

drivers/net/usb/cdc_ether.c | 6 +++---
drivers/usb/core/generic.c | 6 +++---
drivers/usb/gadget/function/f_rndis.c | 6 +++---
include/uapi/linux/usb/cdc.h | 3 +++
4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 2a32d91..9c216c2 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -35,9 +35,9 @@

static int is_rndis(struct usb_interface_descriptor *desc)
- return (desc->bInterfaceClass == USB_CLASS_COMM&&
- desc->bInterfaceSubClass == 2&&
- desc->bInterfaceProtocol == 0xff);
+ return (desc->bInterfaceClass == USB_CLASS_MISC&&
+ desc->bInterfaceSubClass == USB_CDC_SUBCLASS_RNDIS&&
+ desc->bInterfaceProtocol == USB_CDC_RNDIS_PROTO_ETH);

Does that mean that new kernels will stop working with old RNDIs
gadgets because they stop recognising them as RNDIS? I feel like this
function should accept both, i.e.:

Hmm.. I am not a usb guru ... but I think, yes, you are right.
I add this to a v2 (if this patch has a chance to go in mainline).


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