Re: [PATCH] cxl/hdm: allow zero sized committed decoders

[Gregory Price]

On Sat, Oct 04, 2025 at 01:49:26PM +0000, Vishal Aslot wrote:
> >>
> >
> > Ahhh, so are you saying that you will only ever observe the following
> > (as an example)
> >
> > endpoint decoders...
> > decoder2.0   ->  available and can be programmed
> > decoder2.1   ->  size=0, locked
> > ...
> > decoder2.N   ->  size=0, locked
> >
> > or are you suggesting the following is valid:
> >
> > decoder2.0   ->  size=0, locked
> > decoder2.1   ->  available and can be programmed
> > ...
> > decoder2.N   ->  available and can be programmed
> >
> > ~Gregory
> 
> The first case is what we've got. In our case, the HB has 4 decoders. The end point (a Montage card with single port) has two decoders. For both, we commit & lock all decoders and all decoders except decoder<port>.0 are zero-sized.

If the second case is not supported (I don't think it is), then it's
worth spelling this out.

I don't think either of these cases are relevant for scenarios outside
of the scenario where the host pre-configures the decoders either -
worth spelling that out as well.

Just in the commit log.

~Gregory