From: khilman@ti•com (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv2 04/19] ARM: OMAP4: PM: save/restore all DPLL settings in OFF mode
Date: Wed, 30 May 2012 15:09:49 -0700 [thread overview]
Message-ID: <87mx4p5niq.fsf@ti.com> (raw)
In-Reply-To: <CAOMWX4ewVauzYW9pJq07=moLcgkBLyvx68o7T8975cGvshfK3Q@mail.gmail.com> (Nishanth Menon's message of "Wed, 30 May 2012 13:24:17 -0500")
"Menon, Nishanth" <nm@ti•com> writes:
> On Wed, May 30, 2012 at 12:59 PM, Kevin Hilman <khilman@ti•com> wrote:
>> "Menon, Nishanth" <nm@ti•com> writes:
>>
>>> On Thu, May 17, 2012 at 3:52 AM, Shilimkar, Santosh
>>> <santosh.shilimkar@ti•com> wrote:
>>>> On Thu, May 17, 2012 at 12:34 PM, Shilimkar, Santosh
>>>> <santosh.shilimkar@ti•com> wrote:
>>>>> On Thu, May 17, 2012 at 4:12 AM, Kevin Hilman <khilman@ti•com> wrote:
>>>>>> Tero Kristo <t-kristo@ti•com> writes:
>>>>>>
>>> [...]
>>>>>> - Rather than hooking into omap4_enter_lowpower(), should use
>>>>>> ?the cluster PM enter/exit notifier chain.
>>>>>>
>>>>> This is again specific to device OFF only and not related to CPU
>>>>> cluster state as such. So I don't think notifiers should be used here.
>>>>>
>>>>> O.w even when we attempt just MPU OSWR C-state, all these functions will
>>>>> get called in notifier chain.
>>>>>
>>>> Just a thought, we can have a separate notifier chain for device OFF. It can
>>>> allow use to get rid of 'enable_off_mode" kind of flags and can be
>>>> used by many drivers too.
>>>
>>> Like the overall idea, but one minor dumb concern might be sequencing
>>> of notifiers
>>> ?- OFF entry and restore needs things to be executed in a specific sequence.
>>> How do we plan to ensure the sequence is maintained in a notifier call
>>> chain? one
>>> possible option might be a "priority" based scheme?
>>
>> Or just combine the events that need a specific sequence into single
>> notifier callback function.
> There is other issues in case of failure cases -> abort of OFF
> sequence due to pending interrupt
> detected as part of a notifier - error handling needs to be sane in
> proper sequence.
> I understand and appreciate the intent of replacing the single mega
> enter_sleep with a chain of notifiers
> but any such option will need to be scalable enough to handle weird
> erratum handling (HSI CAWAKE as an example)
> which potentially break the logic flow and be either be equal or
> better than what we have today interms of
> error handling. since these notifiers will be triggered for
> CPUIDLE(performance sensitive) and suspend, the intricacies
> might be better understood by seeing how this proposed notifiers look like.
Makes sense. Thanks for clarifying.
What $SUBJECT series proposed was indeed a "mega function", but one that
was just a list of function calls with no error checking or recovery,
and no documentation/description about dependencies/sequencing etc. etc.
Based on the patches at hadn (which is all reviewers have to go on),
notifiers seemed to be a good fit.
If there are good reasons that all of the device-off events need to be
coordinated/synchronized/sequenced (and it sounds like there are, thanks
for pointing them out), I am not opposed to that approach. It simply
needs to be well described in the changlog.
Thanks,
Kevin
next prev parent reply other threads:[~2012-05-30 22:09 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-14 10:18 [PATCHv2 00/19] ARM: OMAP4: device off support Tero Kristo
2012-05-14 10:18 ` [PATCHv2 01/19] ARM: OMAP4: PM: powerdomain: Add HWSAR flag to L3INIT Tero Kristo
2012-05-16 18:27 ` Kevin Hilman
2012-05-14 10:18 ` [PATCHv2 02/19] ARM: OMAP4: Add SAR ROM base address Tero Kristo
2012-05-16 18:28 ` Kevin Hilman
2012-05-21 8:28 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 03/19] ARM: OMAP4: PM: Add device-off support Tero Kristo
2012-05-16 22:36 ` Kevin Hilman
2012-05-17 7:10 ` Shilimkar, Santosh
2012-05-21 8:48 ` Tero Kristo
2012-05-21 14:05 ` Jean Pihet
2012-05-29 18:34 ` Kevin Hilman
2012-05-29 18:31 ` Kevin Hilman
2012-05-30 8:20 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 04/19] ARM: OMAP4: PM: save/restore all DPLL settings in OFF mode Tero Kristo
2012-05-16 22:42 ` Kevin Hilman
2012-05-17 7:04 ` Shilimkar, Santosh
2012-05-17 8:52 ` Shilimkar, Santosh
2012-05-17 16:37 ` Kevin Hilman
2012-05-21 9:01 ` Tero Kristo
2012-05-29 19:46 ` Menon, Nishanth
2012-05-30 17:59 ` Kevin Hilman
2012-05-30 18:24 ` Menon, Nishanth
2012-05-30 22:09 ` Kevin Hilman [this message]
2012-05-31 2:38 ` Shilimkar, Santosh
2012-05-21 8:58 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 05/19] ARM: OMAP4: PM: save/restore all CM1/2 " Tero Kristo
2012-05-16 22:48 ` Kevin Hilman
2012-05-17 7:05 ` Shilimkar, Santosh
2012-05-14 10:18 ` [PATCHv2 06/19] ARM: OMAP4: PM: Add SAR backup support towards device OFF Tero Kristo
2012-05-16 22:58 ` Kevin Hilman
2012-05-17 7:02 ` Shilimkar, Santosh
2012-05-17 16:42 ` Kevin Hilman
2012-05-18 5:53 ` Shilimkar, Santosh
2012-05-21 9:07 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 07/19] ARM: OMAP4: Auto generate SAR layout contents Tero Kristo
2012-05-14 10:18 ` [PATCHv2 08/19] ARM: OMAP4: SAR: generate overwrite data based on SAR ROM contents Tero Kristo
2012-05-14 10:18 ` [PATCHv2 09/19] ARM: OMAP4: PM: add errata support Tero Kristo
2012-05-29 20:10 ` Menon, Nishanth
2012-05-30 8:32 ` Tero Kristo
2012-05-30 14:45 ` Menon, Nishanth
2012-05-14 10:18 ` [PATCHv2 10/19] ARM: OMAP4: PM: Work-around for ROM code BUG of IVAHD/TESLA Tero Kristo
2012-05-16 23:05 ` Kevin Hilman
2012-05-16 23:07 ` Kevin Hilman
2012-05-21 9:11 ` Tero Kristo
2012-05-29 20:13 ` Kevin Hilman
2012-05-17 6:52 ` Shilimkar, Santosh
2012-05-17 16:45 ` Kevin Hilman
2012-05-18 5:55 ` Shilimkar, Santosh
2012-05-14 10:18 ` [PATCHv2 11/19] ARM: OMAP4: PM: save/restore CM L3INSTR registers when MPU hits OSWR/OFF mode Tero Kristo
2012-05-16 23:17 ` Kevin Hilman
2012-05-17 6:53 ` Shilimkar, Santosh
2012-05-14 10:18 ` [PATCHv2 12/19] ARM: OMAP4: PM: update ROM return address for OSWR and OFF Tero Kristo
2012-05-16 23:36 ` Kevin Hilman
2012-05-21 9:29 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 13/19] ARM: OMAP4: PM: Mark the PPI and SPI interrupts as non-secure for GP Tero Kristo
2012-05-16 23:48 ` Kevin Hilman
2012-05-21 9:32 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 14/19] ARM: OMAP4: wakeupgen: enable clocks for save_secure_all Tero Kristo
2012-05-17 0:06 ` Kevin Hilman
2012-05-21 9:38 ` Tero Kristo
2012-05-21 9:43 ` Shilimkar, Santosh
2012-05-29 20:15 ` Kevin Hilman
2012-05-29 20:48 ` Menon, Nishanth
2012-05-30 8:44 ` Tero Kristo
2012-05-30 8:33 ` Tero Kristo
2012-05-17 0:17 ` Paul Walmsley
2012-05-21 9:35 ` Tero Kristo
2012-05-21 9:39 ` Shilimkar, Santosh
2012-05-14 10:18 ` [PATCHv2 15/19] ARM: OMAP4430: PM: workaround for DDR corruption on second CS Tero Kristo
2012-05-17 0:15 ` Kevin Hilman
2012-05-17 7:12 ` Shilimkar, Santosh
2012-05-17 16:47 ` Kevin Hilman
2012-05-18 5:55 ` Shilimkar, Santosh
2012-05-14 10:18 ` [PATCHv2 16/19] TEMP: ARM: OMAP4: prevent voltage transitions Tero Kristo
2012-05-14 10:18 ` [PATCHv2 17/19] ARM: OMAP4: put cpu1 back to sleep if no wake request Tero Kristo
2012-05-17 0:31 ` Kevin Hilman
2012-05-21 10:21 ` Tero Kristo
2012-05-21 10:40 ` Shilimkar, Santosh
2012-05-29 20:17 ` Kevin Hilman
2012-05-30 15:18 ` Menon, Nishanth
2012-05-14 10:18 ` [PATCHv2 18/19] ARM: OMAP4460: wakeupgen: set GIC_CPU0 backup status flag always Tero Kristo
2012-05-17 0:33 ` Kevin Hilman
2012-05-21 9:12 ` Tero Kristo
2012-05-14 10:18 ` [PATCHv2 19/19] ARM: OMAP4: powerdomain: update mpu / core off counters during device off Tero Kristo
2012-05-30 21:08 ` Menon, Nishanth
2012-05-31 6:50 ` Tero Kristo
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