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From: khilman@ti•com (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv2 17/19] ARM: OMAP4: put cpu1 back to sleep if no wake request
Date: Tue, 29 May 2012 13:17:09 -0700	[thread overview]
Message-ID: <87likag2t6.fsf@ti.com> (raw)
In-Reply-To: <CAMQu2gy0Lwga0gDhT7+iOFM6ZLPnW4Q0qo_r4=cW6L4s5fbLZw@mail.gmail.com> (Santosh Shilimkar's message of "Mon, 21 May 2012 16:10:10 +0530")

"Shilimkar, Santosh" <santosh.shilimkar@ti•com> writes:

> Tero,
>
> On Mon, May 21, 2012 at 3:51 PM, Tero Kristo <t-kristo@ti•com> wrote:
>> On Wed, 2012-05-16 at 17:31 -0700, Kevin Hilman wrote:
>>> Tero Kristo <t-kristo@ti•com> writes:
>>>
>>> > If AUX_CORE_BOOT0 does not indicate wakeup request for cpu1, put it back
>>> > to off.
>>>
>>> Why is it waking up then? ?(I know the answer, but will forget. ?The
>>> changelog serves as my long-term memory.)
>>
>> Will add comment. (Both cpus will wake-up after device-off reset.)
>>
>>>
>>> > This is needed during wakeup from device off to prevent cpu1
>>> > from being stuck indefinitely in the wakeup loop
>>>
>>> Why does it get stuck?
>>
>> Related to the above, if the AUX_CORE_BOOT0 is not set, the code will
>> wait for it indefinitely in busy loop.
>>
>>>
>>> > and also to prevent wakeup problem on GP chips with device off mode.
>>>
>>> What wakeup problem?
>>
>> This is apparently related to the GIC restore issue addressed with patch
>> 3/8 of the core-ret set (workaround for the ROM bug because of CA9 r2pX
>> gic register change), the interrupts get disabled. Maybe Santosh has
>> some comments on this one.
>>>
> Not sure what you mean wakeup issue on GP device.
>
> IIUC, the issue is:
> Wakeup from device OFF, hardware releases the reset for both CPUs,
> This is special case and applicable only for device OFF. The reason
> CPU1 needs to be hold back, because the security SW is affined with
> CPU0 which needs to be up and running for any of the ROM code APIs
> to work. Like setting up SMP bit, AUX control etc. Without CPU0 booted,
> CPU1 won't be able to execute those ROM functions and hence won't be
> able to boot properly.

That's a nice description of the problem.  Please incorporate a summary
like this into the changlog to describe the problem, then describe the
solution.

Thanks,

Kevin


> I think the limitation is applicable to all OMAP4 devices as well as OMAP5
> devices.

  reply	other threads:[~2012-05-29 20:17 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
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 [this message]
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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