From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752584Ab0EQPy7 (ORCPT ); Mon, 17 May 2010 11:54:59 -0400 Received: from eu1sys200aog103.obsmtp.com ([207.126.144.115]:37302 "EHLO eu1sys200aog103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261Ab0EQPy6 (ORCPT ); Mon, 17 May 2010 11:54:58 -0400 Subject: Re: [PATCH 1/1] regulator: return set_mode is same mode is requested From: Sundar R Iyer Reply-To: To: Mark Brown Cc: "linux-kernel@vger.kernel.org" , STEricsson_nomadik_linux , Liam Girdwood , Linus WALLEIJ In-Reply-To: <20100517153431.GA6218@opensource.wolfsonmicro.com> References: <1274105393-32197-1-git-send-email-sundar.iyer@stericsson.com> <20100517144411.GD5257@opensource.wolfsonmicro.com> <1274108214.20589.28.camel@bnru01> <1274109402.20589.39.camel@bnru01> <20100517153431.GA6218@opensource.wolfsonmicro.com> Content-Type: text/plain Organization: STEricsson Date: Mon, 17 May 2010 21:24:48 +0530 Message-ID: <1274111688.20589.54.camel@bnru01> MIME-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 Cc: Mark Brown Acked-by: Linus Walleij Signed-off-by: Sundar R Iyer --- 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) -- 1.7.0