linux-kernel - Re: [PATCH v2] i2c: exynos5: Properly use the "noirq" variants of suspend/resume

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Message-ID: <CAD=FV=WSuxbTg2g-Cb79fFQKV4+_Gtc4PUQ4poovNM0eUkkMeg@mail.gmail.com>
Date:	Wed, 25 Jun 2014 09:33:32 -0700
From:	Doug Anderson <dianders@...omium.org>
To:	Kukjin Kim <kgene.kim@...sung.com>
Cc:	Wolfram Sang <wsa@...-dreams.de>,
	Tomasz Figa <tomasz.figa@...il.com>,
	Javier Martinez Canillas <javier.martinez@...labora.co.uk>,
	naveen krishna <ch.naveen@...sung.com>,
	Jingoo Han <jg1.han@...sung.com>,
	Jean Delvare <jdelvare@...e.de>, Simon Glass <sjg@...gle.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Masanari Iida <standby24x7@...il.com>,
	Sachin Kamat <sachin.kamat@...aro.org>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] i2c: exynos5: Properly use the "noirq" variants of suspend/resume

Kukjin,

On Wed, Jun 25, 2014 at 4:13 AM, Kukjin Kim <kgene.kim@...sung.com> wrote:
> Doug Anderson wrote:
>>
>> The original code for the exynos i2c controller registered for the
>> "noirq" variants.  However during review feedback it was moved to
>> SIMPLE_DEV_PM_OPS without anyone noticing that it meant we were no
>> longer actually "noirq" (despite functions named
>> exynos5_i2c_suspend_noirq and exynos5_i2c_resume_noirq).
>>
>> i2c controllers that might have wakeup sources on them seem to need to
>> resume at noirq time so that the individual drivers can actually read
>> the i2c bus to handle their wakeup.
>>
>> NOTE: I took the original review feedback from Wolfram and added
>> poweroff, thaw, freeze, restore.
>>
> Yeah I'm not sure except .suspend_noirq and .resume_noirq but I'm fine if
> Wolfram suggested ;-)

Sorry, I didn't mean to imply that Wolfram suggested the "noirq" versions.

Specifically in <https://lkml.org/lkml/2013/9/8/133> Naveen had:

> +static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
> + .suspend_noirq = exynos5_i2c_suspend_noirq,
> + .resume_noirq = exynos5_i2c_resume_noirq,
> +};
> +
> +#define EXYNOS5_DEV_PM_OPS (&exynos5_i2c_dev_pm_ops)
> +#else
> +#define EXYNOS5_DEV_PM_OPS NULL
> +#endif

And Wolfram said:

> Isn't there a macro for this? SIMPLE_DEV_PM_OPS*? Not sure, I always mix
> them up...

That had the side effect of getting freeze, restore, ...

Ah, I also see that Felipe Balbi was the one that gave earlier
feedback about this also at <https://lkml.org/lkml/2012/11/27/262>.
He said "you need to define poweroff, thaw, freeze, restore."


>> This patch has only been compile-tested since I don't have all the
>> patches needed to make my machine using this i2c driver actually
>> suspend/resume.
>>
>> Signed-off-by: Doug Anderson <dianders@...omium.org>
>> ---
>> Changes in v2:
>> - Added missing CONFIG_PM_SLEEP
>>
>>  drivers/i2c/busses/i2c-exynos5.c | 12 ++++++++++--
>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-
>> exynos5.c
>> index 63d2292..348b1cd 100644
>> --- a/drivers/i2c/busses/i2c-exynos5.c
>> +++ b/drivers/i2c/busses/i2c-exynos5.c
>> @@ -789,8 +789,16 @@ static int exynos5_i2c_resume_noirq(struct device *dev)
>>  }
>>  #endif
>>
>> -static SIMPLE_DEV_PM_OPS(exynos5_i2c_dev_pm_ops, exynos5_i2c_suspend_noirq,
>> -                      exynos5_i2c_resume_noirq);
>> +const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
>
> Maybe static const struct...?

Duh, right.  Fixing and will spin.


>> +#ifdef CONFIG_PM_SLEEP
>> +     .suspend_noirq = exynos5_i2c_suspend_noirq,
>> +     .resume_noirq = exynos5_i2c_resume_noirq,
>> +     .freeze_noirq = exynos5_i2c_suspend_noirq,
>> +     .thaw_noirq = exynos5_i2c_resume_noirq,
>> +     .poweroff_noirq = exynos5_i2c_suspend_noirq,
>> +     .restore_noirq = exynos5_i2c_resume_noirq,
>> +#endif
>> +};
>>
>>  static struct platform_driver exynos5_i2c_driver = {
>>       .probe          = exynos5_i2c_probe,
>> --
>> 2.0.0.526.g5318336
>
> Others look good to me,
>
> Acked-by: Kukjin Kim <kgene.kim@...sung.com>
>
> Thanks,
> Kukjin
>
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