USB device debugging

[Narasimha M]

Thanks for the info. Sorry to ask you again, where does the usb driver
(GobiNet in my case) comes into picture in receive packet flow. I
suspect that the driver has to send some data (may be with some
interrupts) to rx_complete and then it will go to rx_submit. Is my
understanding is correct ? or if rx_submit is the first function to
generate the data, then where does Gobinet driver comes into place.
Could you please explain. I don't know how some usb driver works. This
is the first time i am working on it.

On Wed, May 25, 2016 at 4:36 PM, Bjørn Mork <bjorn at mork.no> wrote:
> Narasimha M <mnarasimha786 at gmail.com> writes:
>
>> I am able to see the corrupted data in rx_complete itself.
>
> Then the only likely source is the device.  In theory it could be the
> host controller, but that is very unliekely unless you use some
> out-of-tree driver there too.
>
> You can easily verify that usbnet can be ruled out by follwing the
> earlier usbmon advice.
>
>> What are
>> the possibilities for the data corruption in rx_complete. Any fixes to
>> resolve this. And from where the data in rx_submit generates
>
> rx_submit allocates new buffers using __netdev_alloc_skb_ip_align() like
> many other network drivers.
>
>
>
> Bjørn



-- 
Narasimha