From: khilman@kernel•org (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/9] PM / Domains: Remove dev->driver check for runtime PM
Date: Fri, 21 Aug 2015 14:04:20 -0700 [thread overview]
Message-ID: <7hio88gxpn.fsf@deeprootsystems.com> (raw)
In-Reply-To: <CAMuHMdV2gDBaPRb3yE=tVPO_pr7PFA6bwhyQE5raumCh_qPXww@mail.gmail.com> (Geert Uytterhoeven's message of "Sun, 16 Aug 2015 11:24:51 +0200")
Geert Uytterhoeven <geert@linux-m68k•org> writes:
> Hi Kevin,
>
> On Fri, Aug 14, 2015 at 7:19 PM, Kevin Hilman <khilman@kernel•org> wrote:
>> On Fri, Aug 14, 2015 at 12:24 AM, Geert Uytterhoeven
>> <geert@linux-m68k•org> wrote:
>>> On Fri, Aug 14, 2015 at 5:40 AM, Kevin Hilman <khilman@kernel•org> wrote:
>>>> Geert Uytterhoeven <geert@linux-m68k•org> writes:
>>>>> On Wed, Aug 12, 2015 at 9:50 PM, Kevin Hilman <khilman@kernel•org> wrote:
>>>>>> This check might have made sense before PM domains, but with PM domains,
>>>>>> it's entirely possible to have a simple device without a driver and the
>>>>>> PM domain handles all the necesary PM, so I think this check
>>>>>> could/should be removed.
>>>>>>
>>>>>> Thoughts?
>>>>>
>>>>> Simple devices without a driver aren't handled automatically.
>>>>> At minimum, the driver should call pm_runtime_enable(), cfr.
>>>>> drivers/bus/simple-pm-bus.c.
>>>>
>>>> That's correct, and in the proof-of-concept stuff I hacked up and in
>>>> Lina's series, the CPU "devices" do indeed to this. Without that, they
>>>> wouldn't end up ever taking this codepath through genpd's
>>>> runtime_suspend and power_off hooks.
>>>>
>>>> Also, I'm not sure if your comment was meant to be an objection to the
>>>> patch? or if you're OK with it.
>>>
>>> My comment was purely meant as a response to "it's entirely possible to have a
>>> simple device without a driver and the PM domain handles all the necesary PM".
>>
>> Right, so if the PM domain does the pm_runtime_enable() for these
>> "simple" devices without drivers, they can still exist without a
>> driver, and the PM domain doing all the magic.
>
> Is it possible to let the PM Domain do the pm_runtime_enable() itself in
> the absence of a driver?
Well, I suppose it's possible, not sure it's recommended. :)
> If yes, I wouldn't have needed simple-pm-bus.c.
> What if a driver is bound later?
Yeah, you're approach is better.
Kevin
next prev parent reply other threads:[~2015-08-21 21:04 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-04 23:35 [PATCH 0/9] ARM: PM / Domains: Generic PM domains for CPUs/Clusters Lina Iyer
2015-08-04 23:35 ` [PATCH 1/9] PM / Domains: Allocate memory outside domain locks Lina Iyer
2015-08-12 19:47 ` Kevin Hilman
2015-09-01 12:40 ` Ulf Hansson
2015-08-04 23:35 ` [PATCH 2/9] PM / Domains: Remove dev->driver check for runtime PM Lina Iyer
2015-08-12 19:50 ` Kevin Hilman
2015-08-13 8:57 ` Geert Uytterhoeven
2015-08-14 3:40 ` Kevin Hilman
2015-08-14 7:24 ` Geert Uytterhoeven
2015-08-14 17:19 ` Kevin Hilman
2015-08-16 9:24 ` Geert Uytterhoeven
2015-08-21 21:04 ` Kevin Hilman [this message]
2015-08-24 19:50 ` Lina Iyer
2015-08-25 9:24 ` Geert Uytterhoeven
2015-09-01 13:28 ` Ulf Hansson
2015-08-04 23:35 ` [PATCH 3/9] PM / Domains: Support IRQ safe PM domains Lina Iyer
2015-08-12 20:12 ` Kevin Hilman
2015-08-12 20:47 ` Lina Iyer
2015-08-12 23:03 ` Stephen Boyd
2015-08-04 23:35 ` [PATCH 4/9] kernel/cpu_pm: fix cpu_cluster_pm_exit comment Lina Iyer
2015-08-12 20:13 ` Kevin Hilman
2015-08-04 23:35 ` [PATCH 5/9] ARM: common: Introduce PM domains for CPUs/clusters Lina Iyer
2015-08-06 3:14 ` Rob Herring
2015-08-07 23:45 ` Kevin Hilman
2015-08-11 13:07 ` Geert Uytterhoeven
2015-08-11 15:58 ` Lina Iyer
2015-08-11 20:12 ` Rob Herring
2015-08-11 22:29 ` Lina Iyer
2015-08-12 19:00 ` [PATCH v2 1/2] " Lina Iyer
2015-08-12 19:00 ` [PATCH v2 2/2] ARM: domain: Add platform handlers for CPU PM domains Lina Iyer
2015-08-13 17:29 ` [PATCH v2 1/2] ARM: common: Introduce PM domains for CPUs/clusters Rob Herring
2015-08-13 20:12 ` Lina Iyer
2015-08-13 22:01 ` Rob Herring
2015-08-14 14:38 ` Lina Iyer
2015-08-13 15:01 ` [PATCH 5/9] " Lorenzo Pieralisi
2015-08-13 15:45 ` Lina Iyer
2015-08-13 15:52 ` Lorenzo Pieralisi
2015-08-13 16:22 ` Lina Iyer
2015-08-14 3:51 ` Kevin Hilman
2015-08-14 4:02 ` Lina Iyer
2015-08-14 15:49 ` Lorenzo Pieralisi
2015-08-14 19:11 ` Kevin Hilman
2015-08-13 17:26 ` Sudeep Holla
2015-08-13 19:27 ` Lina Iyer
2015-08-14 9:52 ` Sudeep Holla
2015-08-04 23:35 ` [PATCH 6/9] ARM: domain: Add platform handlers for CPU PM domains Lina Iyer
2015-08-05 14:45 ` Rob Herring
2015-08-05 16:38 ` Lina Iyer
2015-08-05 19:23 ` Lina Iyer
2015-08-06 3:01 ` Rob Herring
2015-08-10 15:36 ` Lina Iyer
2015-08-04 23:35 ` [PATCH 7/9] ARM: cpuidle: Add runtime PM support for CPU idle Lina Iyer
2015-08-04 23:35 ` [PATCH 8/9] ARM64: smp: Add runtime PM support for CPU hotplug Lina Iyer
2015-08-04 23:35 ` [PATCH 9/9] ARM: " Lina Iyer
2015-08-12 20:28 ` Kevin Hilman
2015-08-12 20:43 ` Lina Iyer
2015-08-14 18:59 ` Kevin Hilman
2015-08-12 23:47 ` Stephen Boyd
2015-08-13 16:00 ` Lina Iyer
2015-08-13 19:18 ` Stephen Boyd
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