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

From: Doug Anderson
Date: Wed Jun 25 2014 - 12:33:40 EST


Kukjin,

On Wed, Jun 25, 2014 at 4:13 AM, Kukjin Kim <kgene.kim@xxxxxxxxxxx> 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@xxxxxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxx>
>
> Thanks,
> Kukjin
>
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