[Coco] Fwd: IP packets on my coco

John W. Linville linville at tuxdriver.com
Fri Jun 10 19:36:23 EDT 2016


On Fri, Jun 10, 2016 at 05:27:45PM -0500, Christopher R. Hawks wrote:
> On Fri, 10 Jun 2016 18:03:22 -0400
> Brett Gordon <beretta42 at gmail.com> wrote:
> 
> > The "soft" interrupts (aka polling) that nitros uses is indeed 60 hz.
> > 
> > Brett M Gordon
> > On Jun 10, 2016 4:52 PM, "Dave Philipsen" <dave at davebiz.com> wrote:
> > 
> > > So I have a question since it has been many years since I wrote an
> > > OS9 device driver.  If the driver is written to poll the device
> > > instead of being interrupt driven, how often will it poll the
> > > device to check for the necessity to service it? Once each tick?
> > >
> > > Dave Philipsen
> > >
>    
>     So you'd have to (theoretically) process 20,833 byes each poll at 10
> Mbits/Sec (slowest wired ethernet speed). Slowest WiFi is 11 Mbits/Sec,
> so add 10%.
> 
>     I know that actual data transfer speeds are about 1/2 the max, but,
> that's still a lot of data. Big hardware buffers?

You probably only have one frame (or a small number) queued-up at
any given time.  Any MAC worth using will have a filter so you only
receive frames for your unicast address and any multicast addresses
(including broadcast) that you have subscribed to receive.

In any case, polling is only relevant when you have nothing else to do.
Once you know that packets are incoming, you just process them until
you are done.

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.


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