Re: [PATCH v2 0/6] cxl: Initialization and shutdown fixes

[Robert Richter <rrichter@amd.com>]

On 23.10.24 13:34:36, Dan Williams wrote:
> Robert Richter wrote:

> >  	if (p->state < CXL_CONFIG_COMMIT) {
> > -		dev_dbg(&cxlr->dev, "config state: %d\n", p->state);
> > -		rc = -ENXIO;
> > +		rc = dev_err_probe(&cxlr->dev, -EPROBE_DEFER,
> > +				"region config state: %d\n", p->state);
> 
> I would argue EPROBE_DEFER is not appropriate because there is no
> guarantee that the other members of the region show up, and if they do
> they will re-trigger probe. So "probe must be repeated until all
> endpoints were enumerated" is the case either way. I.e. either more
> endpoint arrival triggers re-probe or EPROBE_DEFER triggers extra
> redundant probing *and* still results in a probe attempts as endpoints
> arrive.
> 
> So a dev_dbg() plus -ENXIO return on uncommited region state is
> expected.

So, the region device keeps failing a probe until all endpoints are
collected. This triggered by cxl_add_to_region() after the region went
into CXL_CONFIG_COMMIT state. Looks reasonable.

The setup I was using showed various probe failures so I 'fixed' this
issue without noticing the region device was reprobed later
successfully. Thanks for explaining.

-Robert