Re: [RESEND PATCH v13 2/8] cxl/mem: Read dynamic capacity configuration from the device

[Jonathan Cameron <jic23@kernel.org>]

...

> > > +	/* A DCD reports between 1 and 8 partitions */
> > > +	if (dc_resp->avail_partition_count == 0 ||
> > > +	    dc_resp->avail_partition_count > CXL_MAX_DC_PARTITIONS) {  
> > 
> > This strikes me as a compatibility issue waiting to happen.  Today the spec
> > supports 8, but maybe in future it will support more and I'd not consider
> > that a backwards compatibility break (which this would make it).  I'd clamp
> > to CXL_MAX_DC_PARITIONS and maybe print with dev_info() if you see something
> > bigger in the wild.
> >   
> I see... I did the below and moved it to the caller
> cxl_dev_dc_identify() so the dev_err/dev_info messages are only printed
> once, since the current function is called in a loop.
> 
> 		avail = dc_resp->avail_partition_count;
> 		if (avail == 0) {
> 			dev_err(dev, "Device reported no DC partitions\n");
> 			return -EIO;
> 		}
> 
> 		/* More than Linux handles is not a reason to refuse DCD */
> 		if (avail > CXL_MAX_DC_PARTITIONS) {
> 			dev_info(dev, "Device reported %u DC partitions, reading the first %u\n",
> 				 avail, CXL_MAX_DC_PARTITIONS);
> 			avail = CXL_MAX_DC_PARTITIONS;
> 		}

Given you don't do anything with most of them I'd just do

		avail = min(avail, CXL_MAX_DC_PARTITIONS);

and not print anything.

Thanks,

Jonathan