Re: [PATCHv4 4/8] ARM: OMAP3: add manual control for mpu / core pwrdm usecounting

From: Jean Pihet <jean.pihet@newoldbits.com>
To: t-kristo@ti.com
Cc: Kevin Hilman <khilman@ti.com>,
	linux-omap@vger.kernel.org, paul@pwsan.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCHv4 4/8] ARM: OMAP3: add manual control for mpu / core pwrdm usecounting
Date: Mon, 6 Aug 2012 12:14:08 +0200	[thread overview]
Message-ID: <CAORVsuUDo7VB3FnbQWJo=zowrviNDNbPM4DtqQMNrYAmOOat4w@mail.gmail.com> (raw)
In-Reply-To: <1343637607.9847.13.camel@sokoban>

Hi Tero,

On Mon, Jul 30, 2012 at 10:40 AM, Tero Kristo <t-kristo@ti.com> wrote:
> On Fri, 2012-07-27 at 12:36 -0700, Kevin Hilman wrote:
>> Tero Kristo <t-kristo@ti.com> writes:
>>
>> > mpu / core powerdomain usecounts are now statically increased
>> > by 1 during MPU activity. This allows the domains to reflect
>> > actual usage, and will allow the usecount to reach 0 just before
>> > all CPUs are ready to idle. Proper powerdomain usecounts are
>> > propageted to voltagedomain level also, and will allow vc
>> > callbacks to be triggered at right point of time.
>> >
>> > Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> > Cc: Paul Walmsley <paul@pwsan.com>
>> > Cc: Kevin Hilman <khilman@ti.com>
>>
>> IMO, the idea is fine, but I'm not crazy about the implementation in
>> powerdomain.c, which is meant for pwrdm generic code.   In particular,
>> I'm not crazy about the pwrdm lookups in powerdomain.c.
>>
>> Since pm<soc>.c already has references to mpu_pwrdm and core_pwrdm, why
>> not just add the pwrdm_clkdm_enable/disable calls directly in pm<soc>.c
>
> I think this was how the patch was in some earlier rev but I thought I'd
> try to be more clever with this. :) I can revert the implementation back
> to this.
Furthermore after the changes in pre/post transitions [1], some more
checks will be needed to identify the transitions on the mpu and core
power domains.

[1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=e055548953355b6e69c56f9e54388845b29b4e97

Regards,
Jean

>
>> Also, the changelog should be a bit more specific about why CORE
>> powerdomain is also handled here when most of the code only talks about
>> the CPU.
>
> Yea, I'll add some beef to this also.
>
> -Tero
>
> --
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