Jumbo frame support for BGE_ASICREV_BCM5714

[YongHyeon PYUN]

On Tue, Mar 15, 2011 at 04:38:44PM -0700, YongHyeon PYUN wrote:
> On Mon, Mar 14, 2011 at 09:40:36PM -0700, Vijay Singh wrote:
> > > As you know, BCM5714, BCM5715 and BCM5780 use unique jumbo frame
> > > scheme that is not compatible with other controllers. All other
> > > Broadcom controllers have better jumbo frame scheme. These
> > > controllers have one send ring, one standard receive producer ring
> > > and one receive return ring. In order to receive jumbo frames on
> > > these controllers you have to increase Rx buffer size to hold 9k
> > > sized jumbo frame. Two Rx modes(standard Rx BDs and extended Rx
> > > BDs) are supported for these controllers. Using extended Rx BDs on
> > > BCM5714/BCM5715/BCM5780 reduces the number of Rx BDs to 256 entries
> > > which shall reduce the performance. I would use standard Rx BDs to
> > > hold 512 entries for RX buffers.
> > >
> > > I think I received jumbo frame support request for these
> > > controllers in past. At that time I had no interests on
> > > implementing it due to severe implementation differences. What is
> > > your main reason to use jumbo frame on this controller? What is
> > > your expectation on performance numbers? I guess no other OSes
> > > support jumbo frame on this controller.
> > 
> > Hi Pyun, I am stuck with this NIC due to it being the one present in
> > the HW platform that I have to support. The performance is expectation
> > is mainly for apps that use large payloads (where something TSO would
> > have helped).
> > 
> 
> Here is experimental patch which I tried not to penalize other
> controllers.  I don't have BCM5714 controllers so I don't know
> whether it works or not. The patch was generated against HEAD and
> it would be cleanly applied to 8.2R/7.4R. Due to large bge(4)
> changes I guess it wouldn't be applied to 7.2R. But I guess you can
> install 8.2R/7.4R to one of your box and experiment this patch for
> a while then you can backport this to 7.2R.
> You can find the patch at the following URL.
> http://people.freebsd.org/~yongari/bge/bge.5714.jumbo.diff
> 

There was a bug in the diff. I updated the diff but URL is the same
as before. If you have downloaded the file, please try again.

> > -vijay