[ofa-general] Re: [PATCHv2] IB/ipoib: S/G and HW checksum support

[James Lentini]

On Tue, 4 Sep 2007, Michael S. Tsirkin wrote:

> > Quoting James Lentini <jlentini at netapp.com>:
> > Subject: Re: [PATCHv2] IB/ipoib: S/G and HW checksum support
> > 
> > 
> > 
> > On Tue, 4 Sep 2007, Michael S. Tsirkin wrote:
> > 
> > > Add module option hw_csum: when set, IPoIB will report S/G
> > > support, and rely on hardware end-to-end transport checksum (ICRC)
> > > instead of software-level protocol checksums.
> > 
> > The purpose of this option would be clearer if the parameter name were 
> > "omit_csum". Calling this "HW checksum" support is misleading because 
> > the term is already used to describe network adapters that calculate 
> > TCP/IP checksums in hardware. I realize that you are using the HW 
> > checksum infrastructure to implement this, but it is really not the 
> > same thing.
> 
> Another reason is that I declare HW_CSUM in the netdev
> feature list. Yea, someone might get confused,
> but "omit checksum" is misleading, too, and is likely to
> scare users away from the feature: the need for end-to-end checksum
> is a widely recognised requirement. 

I agree. Since this isn't an end-to-end checksum, I recommend that be 
made clear to the user.

> So I don't have a better name. Hopefully modinfo documents the 
> option well enough.
> 
> > > Since this will not inter-operate with older IPoIB modules, this 
> > > option is off by default.
> > > 
> > > Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>
> > 
> > Does the S/G support need to be tied to the checksum changes?

Can you separate the S/G support and checksum changes into different 
patches?