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

[Sundar R Iyer <sundar.iyer@stericsson.com>]

On Mon, 2010-05-17 at 16:56 +0200, Sundar R IYER wrote:
> Oops. My bad. I messed by typoing up the commit message.
> Okay. I will add a sanity check for that.
> Okay. I came up across this and hence the change. This is intended when
> the same mode is requested! I will edit the commit message appropriately.

Please find the updated patch below:

>From edab94fefd2e9087f4c27df8d352097ddda2dac0 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 |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 98e5d14..9cb21cd 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 +1755,19 @@ int regulator_set_mode(struct regulator
*regulator, unsigned int mode)
 		goto out;
 	}
 
+	/* sanity check */
+	if (!rdev->desc->ops->get_mode) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* return if the same mode is requested */
+	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)
-- 
1.7.0