From: Pavel Machek <pavel@ucw.cz>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
linux-kernel@vger.kernel.org,
Alexandre Belloni <alexandre.belloni@free-electrons.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Ulf Hansson <ulf.hansson@linaro.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
linux-pm <linux-pm@vger.kernel.org>,
Thibaud Cornic <thibaud_cornic@sigmadesigns.com>,
JB <jb_lescher@sigmadesigns.com>, Mason <slash.tmp@free.fr>,
Kevin Hilman <khilman@kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC 1/2] PM / suspend: Add platform_suspend_target_state()
Date: Sat, 15 Jul 2017 18:46:26 +0200 [thread overview]
Message-ID: <20170715164626.GA1373@amd> (raw)
In-Reply-To: <5864280.u6UQBsuXnA@aspire.rjw.lan>
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Hi!
> > > I had an idea of using an enum type encompassing all of the power states
> > > defined for various platforms and serving both as a registry (to ensure the
> > > uniqueness of the values assigned to the states) and a common ground
> > > between platforms and drivers.
> > >
> > > Something like:
> > >
> > > enum platform_target_state {
> > > PLATFORM_STATE_UNKNOWN = -1,
> > > PLATFORM_STATE_WORKING = 0,
> > > PLATFORM_STATE_ACPI_S1,
> > > PLATFORM_STATE_ACPI_S2,
> > > PLATFORM_STATE_ACPI_S3,
> > > PLATFORM_STATE_MY_BOARD_1_GATE_CLOCKS,
> > > PLATFORM_STATE_MY_BOARD_1_GATE_POWER,
> > > PLATFORM_STATE_ANOTHER_BOARD_DO_CRAZY_STUFF,
> > > ...
> > > };
> > >
> > > and define ->target_state to return a value of this type.
> > >
> > > Then, if a driver sees one of these and recognizes that value, it should
> > > know exactly what to do.
> >
> > Remind me why this is good idea?
>
> Because there are drivers that need to do specific things during
> suspend on a specific board when it goes into a specific state as a
> whole.
We have seen driver that cares about voltage to his device being
lost. That's reasonable.
Inquiring what the platform target state is... is not.
> > If board wants to know if certain regulator stays online during
> > suspend, it should invent an API for _that_.
>
> Ideally, yes. However, that may be problematic for multiplatform kernels,
> because they would need to have all of those APIs built in and the driver
> code to figure out which API to use would be rather nasty.
Lets do it the right way. Big enum is wrong.
We already have
struct regulator_state {
int uV; /* suspend voltage */
unsigned int mode; /* suspend regulator operating mode */
int enabled; /* is regulator enabled in this suspend state */
int disabled; /* is the regulator disabled in this suspend state */
};
* struct regulation_constraints - regulator operating constraints.
* @state_disk: State for regulator when system is suspended in disk
* mode.
* @state_mem: State for regulator when system is suspended in mem
* mode.
* @state_standby: State for regulator when system is suspended in
* standby
* mode.
. So it seems that maybe we should tell the drivers if we are entering
"state_mem" or "state_standby" (something I may have opposed, sorry),
then the driver can get neccessary information from regulator
framework.
I don't think it should cause problems with multiplatform kernels.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2017-07-15 16:46 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20170622085102.mpk7vxodpgxtrlfd@piout.net>
2017-06-23 1:08 ` [RFC 0/2] PM / suspend: Add platform_suspend_target_state() Florian Fainelli
2017-06-23 1:08 ` [RFC 1/2] " Florian Fainelli
2017-06-29 23:00 ` Rafael J. Wysocki
2017-07-12 18:08 ` Florian Fainelli
2017-07-14 22:16 ` Rafael J. Wysocki
2017-07-15 6:28 ` Pavel Machek
2017-07-15 12:17 ` Rafael J. Wysocki
2017-07-15 16:46 ` Pavel Machek [this message]
2017-07-15 17:20 ` Florian Fainelli
2017-07-15 18:33 ` Alexandre Belloni
2017-07-06 3:18 ` Pavel Machek
2017-07-16 13:41 ` Alexandre Belloni
2017-07-16 15:35 ` Florian Fainelli
2017-07-15 23:24 ` Rafael J. Wysocki
2017-07-15 23:34 ` Mason
2017-07-15 23:38 ` Rafael J. Wysocki
2017-07-16 2:36 ` Florian Fainelli
2017-07-16 10:22 ` Rafael J. Wysocki
2017-07-16 13:38 ` Alexandre Belloni
2017-07-16 18:24 ` Pavel Machek
2017-07-16 15:41 ` Florian Fainelli
2017-07-15 23:29 ` Rafael J. Wysocki
2017-07-06 3:17 ` Pavel Machek
2017-07-16 10:28 ` Rafael J. Wysocki
2017-07-16 18:22 ` Pavel Machek
2017-06-23 1:08 ` [RFC 2/2] soc: bcm: brcmstb: PM: Implement target_state callback Florian Fainelli
2017-06-29 23:04 ` Rafael J. Wysocki
2017-07-16 2:36 ` [PATCH 0/2] PM / suspend: Add platform_suspend_target_state() Florian Fainelli
2017-07-16 2:36 ` [PATCH 1/2] " Florian Fainelli
2017-07-06 3:18 ` Pavel Machek
2017-07-16 15:41 ` Florian Fainelli
2017-07-16 10:30 ` Rafael J. Wysocki
2017-07-16 2:36 ` [PATCH 2/2] soc: bcm: brcmstb: PM: Implement target_state callback Florian Fainelli
2017-07-17 20:06 ` [PATCH v2] PM / suspend: Add suspend_target_state() Florian Fainelli
2017-07-17 20:16 ` Pavel Machek
2017-07-17 21:03 ` Rafael J. Wysocki
2017-07-17 21:21 ` Florian Fainelli
2017-07-20 8:03 ` Pavel Machek
2017-07-17 22:10 ` [PATCH v3] PM / suspend: Export pm_suspend_target_state Florian Fainelli
2017-07-17 23:24 ` Rafael J. Wysocki
2017-07-18 0:19 ` [PATCH v4] " Florian Fainelli
2017-07-24 20:55 ` Rafael J. Wysocki
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