[PATCH][RFC] usbatm.[ch]: cleanup and OAM F5 loopback

Roman Kagan rkagan at mail.ru
Sun Mar 13 04:17:57 EST 2005

On Fri, Mar 11, 2005 at 09:50:18PM +0100, Duncan Sands wrote:
> > OTOH OAM loopback is as simple as taking the incoming cell, check if it
> > has the same VPI and VCI (for F5), check crc10, change 1 (one!) bit in
> > it, recalculate the crc10 and send it back.  Doesn't seem to be worth
> > letting it go outside the driver.
> if it's simple, then a simple ATM patch sounds the way to go.

I just got another idea.  I tend to think that replying to OAM loopback
cells at an upper layer than SAR is more of a layering violation then
doing it all in the driver.

However it may make sense to create an extra module which will do SAR
and OAM and exchange formatted ATM cells with usbatm (and possibly other
drivers for SAR-incapable devices) on one hand, and cooked ATM skbs with
the atm_dev on the other.

The usbatm then will only be concerned with USB interactions and thus
will become fairly slim and easier to maintain and extend.

Do you think it's worth the effort?


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