[PATCH 0/1] nvme: Export CSTS register via sysfs

[Christoph Hellwig]

On Sat, Mar 20, 2021 at 12:22:08AM +0900, Keith Busch wrote:
> > I think this is a horrible idea.  Userspace has no business touching
> > registers even read-only.  MMIO reads can have side effects as well,
> > intentional or unintentional, and we also open up a whole can of worms
> > of mismatched memory attributes.
> 
> I was thinking the driver wouldn't opt-in if there were read side
> effects, but yeah, it's too fragile. I withdraw the suggestion.

I'd still like to understand what values in CSTS Alan cares about.  I
don't think just dumping a register with somewhat awkward encodings
is a good idea.