2012-08-18 07:07:57

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH] i2c: tegra: Fix ifdefs for suspend mode

On Mon, Jul 30, 2012 at 07:03:07PM +0530, Laxman Dewangan wrote:
> CONFIG_PM covers runtime only PM.

I am a bit confused by this description. CONFIG_PM_RUNTIME covers
runtime PM, no?

>
> Signed-off-by: Laxman Dewangan <[email protected]>
> ---
> This patch will remove the compilation warning if CONFIG_PM_SLEEP
> is not enabled.

Maybe it would help to see the warning?

>
> drivers/i2c/busses/i2c-tegra.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index 66eb53f..9a08c57 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -712,7 +712,7 @@ static int __devexit tegra_i2c_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM
> +#ifdef CONFIG_PM_SLEEP
> static int tegra_i2c_suspend(struct device *dev)
> {
> struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
> --
> 1.7.1.1
>

Regards,

Wolfram

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |


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2012-08-18 12:01:45

by Mark Brown

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Subject: Re: [PATCH] i2c: tegra: Fix ifdefs for suspend mode

On Sat, Aug 18, 2012 at 09:07:32AM +0200, Wolfram Sang wrote:
> On Mon, Jul 30, 2012 at 07:03:07PM +0530, Laxman Dewangan wrote:
> > CONFIG_PM covers runtime only PM.

> I am a bit confused by this description. CONFIG_PM_RUNTIME covers
> runtime PM, no?

The issue is that CONFIG_PM doesn't actually enable any of the PM
callbacks, it only allows you to enable CONFIG_PM_SLEEP and
CONFIG_PM_RUNTIME. This means that if you use CONFIG_PM to protect your
system sleep callbacks they may end up unreferenced if only runtime PM
is enabled.

Personally I'd rather just uncondtionally enable PM rather than faff
around with all these ifdefs...


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2012-08-18 12:12:27

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH] i2c: tegra: Fix ifdefs for suspend mode

On Sat, Aug 18, 2012 at 01:01:38PM +0100, Mark Brown wrote:
> On Sat, Aug 18, 2012 at 09:07:32AM +0200, Wolfram Sang wrote:
> > On Mon, Jul 30, 2012 at 07:03:07PM +0530, Laxman Dewangan wrote:
> > > CONFIG_PM covers runtime only PM.
>
> > I am a bit confused by this description. CONFIG_PM_RUNTIME covers
> > runtime PM, no?
>
> The issue is that CONFIG_PM doesn't actually enable any of the PM
> callbacks, it only allows you to enable CONFIG_PM_SLEEP and
> CONFIG_PM_RUNTIME. This means that if you use CONFIG_PM to protect your
> system sleep callbacks they may end up unreferenced if only runtime PM
> is enabled.

Thanks for the explanation!

Laxman, could you update the description to reflect that?

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |


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