Huawei E3276 problem

Bjørn Mork bjorn at mork.no
Tue Nov 13 02:42:58 PST 2012


Tommy Cheng <tommy7765 at yahoo.com> writes:

> The debug output is as follows: 
>
> # insmod /tmp/cdc_ncm.ko 
> cdc_ncm: 14-Mar-2012
> cdc_ncm 1-1:1.1: XX: ctx->control=81eec080, ctx->data=81eec080, ctx->ether_desc=814b67c8, intf=81eec080
> cdc_ncm 1-1:1.1: XX: failed to claim interface: -16
> usb 1-1: bind() failure
> usbcore: registered new interface driver cdc_ncm

Thanks for testing both of you.  The return code (EBUSY) confirm the
assumption that this fails because we already own the claimed
interface.

I just tested and found that the same patch will apply to both
net-next/master and the current mainline because the context is
unaltered even with the major changes we made to the driver.

So I think I'll try to ask davem if this can be accepted for v3.7 and
stable after all.

Just one more question:  Does unbinding work without any further
changes?  You can test with e.g.
 echo '1-1:1.1' >/sys/bus/usb/drivers/cdc_ncm/unbind

I am wondering because it will attempt to release the data interface
when unbinding from the control interface, and this may cause problems
when they are the same.  In which case we need to put a protecting
conditional there too.



Bjørn


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