Re: [PATCH v1.1 2/2] x86/hpet: Don't enable legacy replacement mode unconditionally

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

I wrote:
> I'm sorry, but I think it is too late for 4.15 to do this.  I prefer
> Jan's patch which I have alread release-acked.
> 
> Can someone qualified please provide a maintainer review for this,
> ideally today ?

I asked Andrew on IRC:

12:08 <Diziet> andyhhp__: Are you prepared to maintainer-ack Jan's
               more-minimal hpet workaround approach ?
12:16 <andyhhp__> Diziet: honestly, no.  I don't consider that
                  acceptable behaviour, and it is a fairly big "f you"
                  (this was literally feedback I got in private) to
                  the downstreams who've spent years trying to get us
                  to fix this bug, and have now backported the first
                  version.
12:16 <andyhhp__> I'm looking into the feedback on my series
12:17 <andyhhp__> one way or another, the moment we enter the fallback
                  path for interrupt routing, something is very broken
                  on the system
12:19 <andyhhp__> so the tradeoff is an unspecified bug on one ancient
                  laptop which can't be tested now, vs 5 years of Atom
                  CPUs, 2 years of latop CPUs, and the forthcoming
                  Server line of Intel CPUs
12:19 <andyhhp__> or whatever other compromise we can work on

I'm sorry that this bug is going to continue to be not properly fixed.
As I understand it the practical impact is that users of those
affected systems (the newer ones you mention) will have to add a
command-line option.  That is, unfortunately, the downside of
time-based releases.  If we had been having this conversation two
weeks ago I would have very likely had a different answer.

I consider the current situation in xen.git#staging-4.15 a blocker for
the release and I want to get the code finalised.  I hope that
Monday's RC will be the last RC and that after that there will be only
docs changes.  That would mean committing a workaround today.

Roger, would you be able to give me a maintainer review of Jan's

 [PATCH][4.15] x86/HPET: don't enable legacy replacement mode unconditionally

?

Andrew, I don't think you have, so far, Nak'd Jan's patch.  If you
feel it warrants your Nak please provide it ASAP.

Thanks,
Ian.