[PATCH 2/9] nvme: use nvme_wait_ready in nvme_shutdown_ctrl

[Keith Busch]

On Wed, Nov 30, 2022 at 03:27:29PM +0100, Pankaj Raghav wrote:
> On 2022-11-30 14:57, Christoph Hellwig wrote:
> > From 2f862232c4428d57dcfdc3b332866a9b2743711d Mon Sep 17 00:00:00 2001
> > From: Christoph Hellwig <hch at lst.de>
> > Date: Wed, 16 Nov 2022 08:54:26 +0100
> > Subject: nvme: use nvme_wait_ready in nvme_shutdown_ctrl
> > 
> > Refactor the code to wait for CSTS state changes so that it can be reused
> > by nvme_shutdown_ctrl.
> > 
> > Signed-off-by: Christoph Hellwig <hch at lst.de>
> 
> One minor nit: I also notice that nvme_wait_ready busy loop sleeps for
> 1~2ms, while the existing shutdown code busy loop sleeps for 100ms. Though,
> I don't think it is an issue.
> 
> Apart from that, the new version looks good to me. Feel free to add to it:

That is indeed a difference, but it's probably a good one. It should
tighten up the time to shutdown more closely to the hardware's
completion, and there's probably some environment where the 10's of
millisecs saved might be meaningful.