Re: [PATCH 1/1] regulator: return set_mode is same mode is requested

[Liam Girdwood <lrg@slimlogic.co.uk>]

On Mon, 2010-05-17 at 21:24 +0530, Sundar R Iyer wrote:
> On Mon, 2010-05-17 at 17:34 +0200, Mark Brown wrote:
> > This doesn't seem like the right error handling - if the driver has a
> > set_mode() you'd *expect* it to have a get_mode() but there's no need
> > for it to be a strict requirement.
> True. In such a case, even a valid request would be lost! So now
> in the updated patch:
>  - check if get_mode is present to avoid oops;
>  - if get_mode is not present, proceed anyways for the request.
> 
> Here is the updated patch:
> 
> >From bad0d5eb51ef84be5b100e3dd0f5a590ea0529b6 Mon Sep 17 00:00:00 2001
> From: Sundar R Iyer <sundar.iyer@stericsson.com>
> Date: Fri, 14 May 2010 15:14:17 +0530
> Subject: [PATCH 1/1] regulator: return set_mode when same mode is requested
> 
> save I/O costs by returning when the same mode is
> requested for the regulator
> 
> Cc: Liam Girdwood <lrg@slimlogic.co.uk>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Acked-by: Linus Walleij <linus.walleij@stericsson.com>
> Signed-off-by: Sundar R Iyer <sundar.iyer@stericsson.com>
> ---
>  drivers/regulator/core.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 98e5d14..2248087 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -1745,6 +1745,7 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode)
>  {
>  	struct regulator_dev *rdev = regulator->rdev;
>  	int ret;
> +	int regulator_curr_mode;
>  
>  	mutex_lock(&rdev->mutex);
>  
> @@ -1754,6 +1755,15 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode)
>  		goto out;
>  	}
>  
> +	/* return if the same mode is requested */
> +	if (rdev->desc->ops->get_mode) {
> +		regulator_curr_mode = rdev->desc->ops->get_mode(rdev);
> +		if (regulator_curr_mode == mode) {
> +			ret = 0;
> +			goto out;
> +		}
> +	}
> +
>  	/* constraints check */
>  	ret = regulator_check_mode(rdev, mode);
>  	if (ret < 0)


Applied.

Thanks

Liam

-- 
Freelance Developer, SlimLogic Ltd
ASoC and Voltage Regulator Maintainer.
http://www.slimlogic.co.uk