Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752626Ab1DPIoX (ORCPT ); Sat, 16 Apr 2011 04:44:23 -0400 Received: from wnohang.net ([178.79.154.173]:50300 "EHLO mail.wnohang.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752005Ab1DPIoW (ORCPT ); Sat, 16 Apr 2011 04:44:22 -0400 X-DKIM: Sendmail DKIM Filter v2.8.3 mail.wnohang.net 795C334870 X-DKIM: Sendmail DKIM Filter v2.8.3 mail.wnohang.net C25E23486D Date: Sat, 16 Apr 2011 14:14:17 +0530 From: Raghavendra D Prabhu To: Richard Purdie Cc: linux-kernel@vger.kernel.org Subject: [PATCH 2/2] FIX: Check the return value before proceeding Message-ID: <20110416084417.GA27829@Xye> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20110416083730.GA5114@Xye> X-Operating-System: Arch linux x86_64 2.6.38.2-bldit-db-FAE X-Editor: VIM - Vi IMproved 7.3 User-Agent: Mutt/1.5.21 (2010-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3067 Lines: 86 In case of failure from lp5521_read, an uninitialized mode is passed to lp5521_write. This adds checks to prevent that. Signed-off-by: Raghavendra D Prabhu --- drivers/leds/leds-lp5521.c | 40 ++++++++++++++++++++++------------------ 1 files changed, 22 insertions(+), 18 deletions(-) diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c index 6c5eac0..f03a524 100644 --- a/drivers/leds/leds-lp5521.c +++ b/drivers/leds/leds-lp5521.c @@ -176,7 +176,7 @@ static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode) ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state); - if (ret == 0){ + if (!ret){ /* set mode only for this engine */ engine_state &= ~(engine->engine_mask); mode &= engine->engine_mask; @@ -192,6 +192,7 @@ static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern) struct lp5521_chip *chip = engine_to_lp5521(eng); struct i2c_client *client = chip->client; int ret; + int ret_read; int addr; u8 mode; @@ -199,23 +200,26 @@ static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern) ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT); /* Mode change requires min 500 us delay. 1 - 2 ms with margin */ usleep_range(1000, 2000); - ret |= lp5521_read(client, LP5521_REG_OP_MODE, &mode); - - /* For loading, all the engines to load mode */ - lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); - /* Mode change requires min 500 us delay. 1 - 2 ms with margin */ - usleep_range(1000, 2000); - lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_LOAD); - /* Mode change requires min 500 us delay. 1 - 2 ms with margin */ - usleep_range(1000, 2000); - - addr = LP5521_PROG_MEM_BASE + eng->prog_page * LP5521_PROG_MEM_SIZE; - i2c_smbus_write_i2c_block_data(client, - addr, - LP5521_PROG_MEM_SIZE, - pattern); - - ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode); + ret_read = lp5521_read(client, LP5521_REG_OP_MODE, &mode); + ret |= ret_read; + + if (!ret_read){ + /* For loading, all the engines to load mode */ + lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); + /* Mode change requires min 500 us delay. 1 - 2 ms with margin */ + usleep_range(1000, 2000); + lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_LOAD); + /* Mode change requires min 500 us delay. 1 - 2 ms with margin */ + usleep_range(1000, 2000); + + addr = LP5521_PROG_MEM_BASE + eng->prog_page * LP5521_PROG_MEM_SIZE; + i2c_smbus_write_i2c_block_data(client, + addr, + LP5521_PROG_MEM_SIZE, + pattern); + + ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode); + } return ret; } -- 1.7.4.4 -------------------------- Raghavendra Prabhu GPG Id : D72BE977 Fingerprint: B93F EBCB 8E05 7039 CD3C A4B8 A616 DCA1 D72B E977 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/