From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Claudiu.Beznea@microchip.com
Cc: linux-kernel@vger.kernel.org, Ludovic.Desroches@microchip.com,
linux-arm-kernel@lists.infradead.org, wenyou.yang@atmel.com
Subject: Re: [PATCH v2 2/3] ARM: at91: pm: add per soc validation of pm modes
Date: Tue, 4 Aug 2020 17:08:41 +0200 [thread overview]
Message-ID: <20200804150841.GA10725@piout.net> (raw)
In-Reply-To: <f9e1d923-225e-7a18-ed48-c8c7e7d4d8cf@microchip.com>
On 04/08/2020 15:00:38+0000, Claudiu.Beznea@microchip.com wrote:
>
>
> On 04.08.2020 14:42, Alexandre Belloni wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >
> > Hello,
> >
> > On 04/08/2020 14:07:37+0300, Claudiu Beznea wrote:
> >> void __init at91rm9200_pm_init(void)
> >> {
> >> + static const int modes[] __initconst = {
> >
> > You don't need that to be static as it is now local to the function.
> >
> >> + AT91_PM_STANDBY, AT91_PM_ULP0
> >> + };
> >> +
> >> if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
> >> return;
> >>
> >> + at91_pm_modes_validate(modes, ARRAY_SIZE(modes));
> >
> > For rm9200 and at91sam9, I would not allow changing the pm_modes and
> > simply enforce standby_mode = AT91_PM_STANDBY and suspend_mode =
> > AT91_PM_ULP0.I don't think you have any user that ever changed that
> > behaviour also that avoids increasing the boot time for those slow SoCs.
>
> OK, but bootargs is parsed at a moment when there is no information about
> the machine that is running the code. And enforcing this in *_pm_init()
> functions for rm9200 and at91sam9 may change suspend and standby mode that
> user selected. If there is no user up to this moment there is still the
> possibility of being one in the future.
>
So let's prevent users from doing that. Unused arguments are silently
ignored which is exactly what we want to do. You won't make me believe
there is actually a use case for swapping the standby and suspend
meanings.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2020-08-04 15:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-04 11:07 [PATCH v2 0/3] AT91 PM improvements Claudiu Beznea
2020-08-04 11:07 ` [PATCH v2 1/3] ARM: at91: pm: add support for ULP0 fast wakeup Claudiu Beznea
2020-08-04 11:07 ` [PATCH v2 2/3] ARM: at91: pm: add per soc validation of pm modes Claudiu Beznea
2020-08-04 11:42 ` Alexandre Belloni
2020-08-04 15:00 ` Claudiu.Beznea
2020-08-04 15:08 ` Alexandre Belloni [this message]
2020-08-04 15:45 ` Claudiu.Beznea
2020-08-04 15:56 ` Alexandre Belloni
2020-08-04 11:07 ` [PATCH v2 3/3] ARM: at91: pm: of_node_put() after its usage Claudiu Beznea
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