From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753809Ab1JaGXP (ORCPT ); Mon, 31 Oct 2011 02:23:15 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:50833 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752283Ab1JaGXO (ORCPT ); Mon, 31 Oct 2011 02:23:14 -0400 Message-ID: <1320042183.5683.1.camel@phoenix> Subject: [PATCH 1/2] mfd: da903x: Ensure setting bits if new value is different from the old value From: Axel Lin To: linux-kernel@vger.kernel.org Cc: Mike Rapoport , Eric Miao , Samuel Ortiz Date: Mon, 31 Oct 2011 14:23:03 +0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.0- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It does not make sense to write new value only when all the bit_mask bits are zero. We need to write new value if the bit mask fields of new value is not equal to old value. Signed-off-by: Axel Lin --- drivers/mfd/da903x.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/mfd/da903x.c b/drivers/mfd/da903x.c index 62ce685..1924b85 100644 --- a/drivers/mfd/da903x.c +++ b/drivers/mfd/da903x.c @@ -182,7 +182,7 @@ int da903x_set_bits(struct device *dev, int reg, uint8_t bit_mask) if (ret) goto out; - if ((reg_val & bit_mask) == 0) { + if ((reg_val & bit_mask) != bit_mask) { reg_val |= bit_mask; ret = __da903x_write(chip->client, reg, reg_val); } -- 1.7.5.4