[openib-general] [PATCH] user_mad: Add receive side RMPP support

[Hal Rosenstock]

On Thu, 2005-06-30 at 17:32, Sean Hefty wrote:
> Roland Dreier wrote:
> > I understand and agree with the sentiment of not wanting to add
> > another ioctl() to get the length.  Instead, how about returning a
> > ib_user_mad_hdr with a status of ENOSPC and putting the actual length
> > somewhere.  I'm not sure if it's better to change the ABI and add a
> > length field to ib_user_mad_hdr, or if we want to return the first 36
> > bytes of an RMPP MAD so the user can figure out the correct length.
> 
> Unless the MAD layer modifies the received MAD, the length may not be set in 
> the header.  Setting this doesn't seem like a big deal.  If it is set, then 
> I'm guessing that we'd want to set the PayloadLength to the value indicated 
> by the spec, but that's not the easiest value to use in order to determine 
> the size of the read.
> 
> Given that, I think that it makes more sense to add a length field to the 
> ib_user_mad_hdr.

That's my conclusion too. ABI change :-(

-- Hal