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

[Alan Adamson]

> On Mar 19, 2021, at 8:30 AM, Christoph Hellwig <hch at lst.de> wrote:
> 
> 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.

Primarily Ready and Failed. I’m reaching out to the requesting team to see if the ’state’ attribute is sufficient.

Back to nvme-cli show-regs, do we just expect this to always fail now our should we be returning good
values?

Alan