linux-kernel - Re: [PATCH] i2c: s3c2410: resume the I2C controller earlier

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Message-ID: <CAD=FV=U0RAS3pi=i7smGo2rBJ+NfijXhmjX1PUs1rrwKkQewPA@mail.gmail.com>
Date:	Wed, 18 Jun 2014 22:23:51 -0700
From:	Doug Anderson <dianders@...omium.org>
To:	Wolfram Sang <wsa@...-dreams.de>,
	Kukjin Kim <kgene.kim@...sung.com>,
	Ben Dooks <ben-linux@...ff.org>
Cc:	Tomasz Figa <tomasz.figa@...il.com>,
	Javier Martinez Canillas <javier.martinez@...labora.co.uk>,
	Vincent Palatin <vpalatin@...omium.org>,
	Doug Anderson <dianders@...omium.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
	"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] i2c: s3c2410: resume the I2C controller earlier

Hi,

On Wed, Jun 18, 2014 at 9:54 PM, Doug Anderson <dianders@...omium.org> wrote:
> From: Vincent Palatin <vpalatin@...omium.org>
>
> When the wake-up is triggered by the PMIC RTC, the RTC driver is trying
> to read the PMIC interrupt status over I2C and fails because the I2C
> controller is not resumed yet.
> Let's resume the I2C controller earlier in the _noirq phase
> (as other hardwares are doing), so we can properly get the wake-up
> condition.
>
> Signed-off-by: Vincent Palatin <vpalatin@...omium.org>
> Signed-off-by: Doug Anderson <dianders@...omium.org>
> ---
>  drivers/i2c/busses/i2c-s3c2410.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index e828a1d..b904132 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -1267,7 +1267,7 @@ static int s3c24xx_i2c_suspend_noirq(struct device *dev)
>         return 0;
>  }
>
> -static int s3c24xx_i2c_resume(struct device *dev)
> +static int s3c24xx_i2c_resume_noirq(struct device *dev)
>  {
>         struct platform_device *pdev = to_platform_device(dev);
>         struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
> @@ -1285,7 +1285,7 @@ static int s3c24xx_i2c_resume(struct device *dev)
>  static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = {
>  #ifdef CONFIG_PM_SLEEP
>         .suspend_noirq = s3c24xx_i2c_suspend_noirq,
> -       .resume = s3c24xx_i2c_resume,
> +       .resume_noirq = s3c24xx_i2c_resume_noirq,

I looked at applying this to another i2c controller and stumbled upon
feedback from Wolfram suggesting that I should add "poweroff, thaw,
freeze, restore".  I'm happy to squash that into this patch or send a
separate patch if people would like it.  Just let me know.

-Doug
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