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Subject: Re: [PATCH v3] nvme-pci: Support shared tags across queues for
 Apple 2018 controllers
From:   Benjamin Herrenschmidt <benh@kernel.crashing.org>
To:     Sagi Grimberg <sagi@grimberg.me>,
        Keith Busch <keith.busch@intel.com>
Cc:     Damien Le Moal <Damien.LeMoal@wdc.com>,
        linux-kernel@vger.kernel.org, Paul Pawlowski <paul@mrarm.io>,
        Jens Axboe <axboe@fb.com>, Minwoo Im <minwoo.im.dev@gmail.com>,
        linux-nvme@lists.infradead.org, Keith Busch <kbusch@kernel.org>,
        Christoph Hellwig <hch@lst.de>
Date:   Tue, 06 Aug 2019 15:26:03 +1000
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On Mon, 2019-08-05 at 11:27 -0700, Sagi Grimberg wrote:
> > > Ping ? I had another look today and I don't feel like mucking
> > > around
> > > with all the AQ size logic, AEN magic tag etc... just for that
> > > sake of
> > > that Apple gunk. I'm happy to have it give up IO tags, it doesn't
> > > seem
> > > to make much of a difference in practice anyway.
> > > 
> > > But if you feel strongly about it, then I'll implement the
> > > "proper" way
> > > sometimes this week, adding a way to shrink the AQ down to
> > > something
> > > like 3 (one admin request, one async event (AEN), and the empty
> > > slot)
> > > by making a bunch of the constants involved variables instead.
> > 
> > I don't feel too strongly about it. I think your patch is fine, so
> > 
> > Acked-by: Keith Busch <keith.busch@intel.com>
> 
> Should we pick this up for 5.3-rc?

Well, if you are talking about just this patch, it's not needed unless
you also merge the rest of the Apple T2 support patches, which some
people I'm sure would like but I think Christoph is a bit cold feet
about (I don't care either way).

If you are talking about the whole series, give me a day or two to
respin with the added check that Keith requested (I believe his ack is
for a respin with the check so setting the IO queue too small doesn't
kill the driver).

Cheers,
Ben.