From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
linux-nvme@lists.infradead.org, sagi@grimberg.me,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Vidya Sagar <vidyas@nvidia.com>
Subject: Re: [PATCH] nvme/pci: default to simple suspend
Date: Fri, 4 Feb 2022 08:10:12 +0100 [thread overview]
Message-ID: <20220204071012.GA28638@lst.de> (raw)
In-Reply-To: <20220202160334.GB3077632@dhcp-10-100-145-180.wdc.com>
On Wed, Feb 02, 2022 at 08:03:34AM -0800, Keith Busch wrote:
> On Wed, Feb 02, 2022 at 08:55:02AM +0100, Christoph Hellwig wrote:
> > On Tue, Feb 01, 2022 at 08:50:06AM -0800, Keith Busch wrote:
> > > There is no complete set of attributes a driver can check to know if
> > > nvme power management is the correct thing to do in a runtime suspend
> > > situation. Every attempt so far to optimize idle power consumption and
> > > resume latency for a particular platform just leads to regressions
> > > elsewhere.
> > >
> > > Default to the simple shutdown since it is the historically safest
> > > option, and provide a user parameter to override it if the user knows
> > > it's safe to use for their platform.
> >
> > Sigh. The platforms really should be asking for a explicit D3cold if
> > they need one..
>
> It's too late now, but perhaps the new property should have been
> inverted since preparing for D3 was the previous default behavior;
> platforms could have instead explicitly asked for "no-D3" if they wanted
> it. That would have been easier for backward compatibility.
I'd really prefer to sort this out at the platform level. We can't work
around broken platforms in nvme forever.
next prev parent reply other threads:[~2022-02-04 7:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-01 16:50 [PATCH] nvme/pci: default to simple suspend Keith Busch
2022-02-01 17:49 ` Vidya Sagar
2022-02-02 7:55 ` Christoph Hellwig
2022-02-02 16:03 ` Keith Busch
2022-02-04 7:10 ` Christoph Hellwig [this message]
2022-02-07 16:06 ` Keith Busch
2022-02-08 14:37 ` Christoph Hellwig
2022-02-08 17:14 ` Keith Busch
2022-02-09 7:48 ` Christoph Hellwig
2022-04-11 13:58 ` Manivannan Sadhasivam
2022-04-23 5:49 ` Christoph Hellwig
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