From: Alan Stern <stern@rowland.harvard.edu>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Phillip Susi <psusi@ubuntu.com>
Cc: Aaron Lu <aaron.lu@intel.com>,
Linux-pm mailing list <linux-pm@vger.kernel.org>
Subject: Allow runtime suspend during system resume
Date: Wed, 8 Jan 2014 15:44:53 -0500 (EST) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1401081522240.1659-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1401081318040.1659-100000@iolanthe.rowland.org>
On Wed, 8 Jan 2014, Alan Stern wrote:
> On Wed, 8 Jan 2014, Alan Stern wrote:
>
> > In essence, you want your disk's state to move directly from unpowered
> > (system asleep) to runtime-suspended with no intermediate active -- but
> > only if the disk doesn't spin up all by itself.
>
> > In the end, it sounds like what you want can be done fairly easily.
>
> It turns out there is a snag. The PM core is set up such that during
> system sleep transitions, there's no way to tell whether or not
> userspace has permitted runtime PM for a device. (This is because the
> core wants to prevent untimely runtime suspends from occurring in the
> middle of a system sleep transition, and to do so it uses the same
> mechanism as it does when userspace disallows runtime suspend.)
>
> As a result, we must not go directly from unpowered to
> runtime-suspended. Not without some sort of change to the PM core.
Rafael:
Right now the PM core does pm_runtime_get_noresume() during the prepare
phase of system sleep, and pm_runtime_put() during the complete phase.
Maybe we should cut down the range of coverage.
For example, we could do the pm_runtime_put() during dpm_resume(), or
even earlier. That way, the resume routine could do something like:
if (!pm_runtime_in_use(dev)) {
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
pm_runtime_enable(dev);
return 0;
}
where pm_runtime_in_use() would check the device's usage counters.
The device would come out of system sleep in a powered-down state, and
could remain runtime-suspended with no need for an extra
power-up/power-down cycle. Isn't this the sort of thing the embedded
people want to do?
As it is, drivers have no way to safely put devices directly into
runtime suspend when coming out of system sleep.
What do you think?
Alan Stern
next prev parent reply other threads:[~2014-01-08 20:44 UTC|newest]
Thread overview: 165+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-17 19:33 [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-07 1:53 ` Phillip Susi
2013-11-07 1:57 ` [PATCH 1/3] sd: don't bother spinning up disks on resume Phillip Susi
2013-11-07 18:21 ` Douglas Gilbert
2013-11-07 21:16 ` Phillip Susi
2013-11-16 18:20 ` James Bottomley
2013-11-17 3:50 ` Phillip Susi
2013-11-17 6:43 ` James Bottomley
2013-11-17 16:15 ` Phillip Susi
2013-11-17 23:54 ` Douglas Gilbert
2013-11-18 1:06 ` Phillip Susi
2013-11-18 15:54 ` Phillip Susi
2013-11-20 14:23 ` Mark Lord
2013-11-20 14:48 ` Phillip Susi
2013-11-28 1:39 ` Phillip Susi
2013-11-18 0:09 ` James Bottomley
2013-11-18 1:11 ` Phillip Susi
2013-11-16 5:23 ` Mark Lord
2013-11-16 14:52 ` Phillip Susi
2013-11-07 1:57 ` [PATCH 2/3] libata: resume in the background Phillip Susi
2013-11-07 1:57 ` [PATCH 3/3] libata: don't start disks on resume Phillip Susi
2013-11-09 1:20 ` [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-09 20:59 ` Phillip Susi
2013-11-09 21:03 ` [PATCH 0/6] Let sleeping disks lie Phillip Susi
2013-12-16 23:30 ` Phillip Susi
2013-12-16 23:30 ` [PATCH 1/6] libata: use sleep instead of standby command Phillip Susi
2013-12-16 23:30 ` [PATCH 2/6] libata: avoid waking disk for several commands Phillip Susi
2013-12-16 23:30 ` [PATCH 3/6] libata: resume in the background Phillip Susi
2014-01-10 22:26 ` Dan Williams
2014-01-11 2:25 ` Phillip Susi
2014-01-11 3:11 ` Dan Williams
2013-12-16 23:30 ` [PATCH 4/6] libata: don't start disks on resume Phillip Susi
2013-12-16 23:30 ` [PATCH 5/6] sd: don't start disks on system resume Phillip Susi
2013-12-17 6:43 ` James Bottomley
2013-12-17 15:01 ` Phillip Susi
2013-12-17 17:48 ` James Bottomley
2013-12-17 18:30 ` Phillip Susi
2013-12-16 23:30 ` [PATCH 6/6] libata: return power status in REQUEST SENSE command Phillip Susi
2013-12-17 18:02 ` Sergei Shtylyov
2013-12-17 18:35 ` Phillip Susi
2014-01-06 2:14 ` REQ_PM vs REQ_TYPE_PM_RESUME Phillip Susi
2014-01-06 7:36 ` Sujit Reddy Thumma
2014-01-06 9:15 ` Aaron Lu
2014-01-06 14:40 ` Phillip Susi
2014-01-06 15:38 ` Alan Stern
2014-01-07 2:44 ` Phillip Susi
2014-01-07 15:20 ` Alan Stern
2014-01-07 15:40 ` Phillip Susi
2014-01-07 15:56 ` Alan Stern
2014-01-09 18:29 ` Douglas Gilbert
2014-01-09 19:20 ` Phillip Susi
2014-01-10 5:23 ` Douglas Gilbert
2014-01-10 14:29 ` Phillip Susi
2014-01-07 7:49 ` Aaron Lu
2014-01-07 14:50 ` Phillip Susi
2014-01-08 1:03 ` Aaron Lu
2014-01-08 1:16 ` Phillip Susi
2014-01-08 1:32 ` Aaron Lu
2014-01-08 1:53 ` Phillip Susi
2014-01-08 2:11 ` Aaron Lu
2014-01-08 2:19 ` Phillip Susi
2014-01-08 2:36 ` Aaron Lu
2014-01-08 5:24 ` Phillip Susi
2014-01-08 7:00 ` Aaron Lu
2014-01-08 19:30 ` Phillip Susi
2014-01-07 15:25 ` Alan Stern
2014-01-07 15:43 ` Phillip Susi
2014-01-07 16:08 ` Alan Stern
2014-01-07 16:37 ` Phillip Susi
2014-01-07 18:05 ` Alan Stern
2014-01-07 18:43 ` Phillip Susi
2014-01-07 19:18 ` Alan Stern
2014-01-07 23:47 ` Phillip Susi
2014-01-08 17:46 ` Alan Stern
2014-01-08 18:31 ` Alan Stern
2014-01-08 20:44 ` Alan Stern [this message]
2014-01-08 21:17 ` Allow runtime suspend during system resume Phillip Susi
2014-01-08 21:34 ` Alan Stern
2014-01-09 10:14 ` Ulf Hansson
2014-01-09 15:41 ` Alan Stern
2014-01-08 22:55 ` Rafael J. Wysocki
2014-01-08 23:24 ` Alan Stern
2014-01-09 0:05 ` Rafael J. Wysocki
2014-01-09 15:32 ` Alan Stern
2014-01-09 15:50 ` Phillip Susi
2014-01-09 16:08 ` Alan Stern
2014-01-09 16:30 ` Phillip Susi
2014-01-09 17:04 ` Alan Stern
2014-01-10 1:25 ` Rafael J. Wysocki
2014-01-10 1:55 ` Phillip Susi
2014-01-10 13:35 ` Rafael J. Wysocki
2014-01-10 14:46 ` Phillip Susi
2014-01-10 15:25 ` Alan Stern
2014-01-10 23:02 ` Rafael J. Wysocki
2014-01-11 2:08 ` Phillip Susi
2014-01-11 22:50 ` Alan Stern
2014-01-12 1:50 ` Phillip Susi
2014-01-11 22:34 ` Alan Stern
2014-01-08 20:20 ` REQ_PM vs REQ_TYPE_PM_RESUME Phillip Susi
2014-01-08 21:21 ` Alan Stern
2014-01-08 21:50 ` Phillip Susi
2014-01-09 1:29 ` Aaron Lu
2014-01-09 12:17 ` Rafael J. Wysocki
2014-01-09 13:18 ` Rafael J. Wysocki
2014-01-09 15:40 ` Alan Stern
2014-01-09 15:53 ` Phillip Susi
2014-01-09 16:14 ` Alan Stern
2014-01-09 16:34 ` Phillip Susi
2014-01-09 17:06 ` Alan Stern
2014-01-16 16:59 ` Disk spin-up optimization during system resume Alan Stern
2014-01-16 18:04 ` Todd E Brandt
2014-01-16 18:33 ` Phillip Susi
2014-01-16 20:05 ` Alan Stern
2014-01-16 22:04 ` Todd E Brandt
2014-01-17 14:57 ` Alan Stern
2014-01-17 19:31 ` Dan Williams
2014-01-17 20:15 ` Alan Stern
2014-01-17 20:24 ` Tejun Heo
2014-01-17 20:55 ` Phillip Susi
2014-01-18 14:04 ` Tejun Heo
2014-01-18 1:36 ` Todd E Brandt
2014-01-18 1:41 ` Alan Stern
2014-01-18 2:15 ` Dan Williams
2014-01-18 2:33 ` Alan Stern
2014-01-18 3:24 ` Phillip Susi
2014-01-18 13:59 ` Tejun Heo
2014-01-17 20:49 ` Phillip Susi
2014-01-17 22:17 ` Dan Williams
2014-01-18 3:18 ` Phillip Susi
2014-01-18 4:09 ` Dan Williams
2014-01-18 14:08 ` Alan Stern
2014-01-21 10:12 ` Dan Williams
2014-01-21 14:37 ` Phillip Susi
2014-01-21 16:03 ` Alan Stern
2014-01-21 16:18 ` Phillip Susi
2014-01-21 16:49 ` Alan Stern
2014-01-21 15:44 ` Alan Stern
2014-01-21 16:18 ` Dan Williams
2014-01-21 16:55 ` Dan Williams
2014-01-20 12:38 ` CrashPlan Pro
2014-01-20 14:30 ` Phillip Susi
2014-01-18 1:24 ` Todd E Brandt
2014-01-18 3:20 ` Phillip Susi
2014-01-16 18:39 ` Phillip Susi
2014-01-16 20:08 ` Alan Stern
2014-01-17 10:16 ` Oliver Neukum
2014-01-17 10:21 ` Tejun Heo
2014-01-17 18:18 ` Alan Stern
2014-01-17 18:39 ` James Bottomley
2014-01-17 19:07 ` Tejun Heo
2013-11-09 21:03 ` [PATCH 1/6] libata: use sleep instead of standby command Phillip Susi
2013-11-09 21:03 ` [PATCH 2/6] libata: avoid waking disk to check power Phillip Susi
2013-11-11 13:05 ` Sergei Shtylyov
2013-11-09 21:03 ` [PATCH 3/6] sd: don't bother spinning up disks on resume Phillip Susi
2013-11-11 13:08 ` Sergei Shtylyov
2013-11-11 14:28 ` Phillip Susi
2013-11-09 21:03 ` [PATCH 4/6] libata: resume in the background Phillip Susi
2013-11-11 13:10 ` Sergei Shtylyov
2013-11-09 21:03 ` [PATCH 5/6] libata: don't start disks on resume Phillip Susi
2013-11-09 21:03 ` [PATCH 6/6] libata: fake some more commands when drive is sleeping Phillip Susi
2013-11-11 16:59 ` [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-11 17:08 ` Phillip Susi
2013-12-17 12:15 ` Tejun Heo
2013-12-17 14:24 ` Phillip Susi
2013-11-27 16:18 ` Phillip Susi
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