From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932129Ab3COPgd (ORCPT ); Fri, 15 Mar 2013 11:36:33 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:1467 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755187Ab3COPgb (ORCPT ); Fri, 15 Mar 2013 11:36:31 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Fri, 15 Mar 2013 08:36:15 -0700 From: Laxman Dewangan To: CC: , , , , , Laxman Dewangan Subject: [PATCH] i2c: tegra: check the clk_prepare_enable() return value Date: Fri, 15 Mar 2013 21:04:08 +0530 Message-ID: <1363361648-10326-1-git-send-email-ldewangan@nvidia.com> X-Mailer: git-send-email 1.7.1.1 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NVIDIA's Tegra SoC allows read/write of controller register only if controller clock is enabled. System hangs if read/write happens to registers without enabling clock. clk_prepare_enable() can be fail due to unknown reason and hence adding check for return value of this function. If this function success then only access register otherwise return to caller with error. Signed-off-by: Laxman Dewangan --- drivers/i2c/busses/i2c-tegra.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 36704e3..b714776 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -411,7 +411,11 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE; u32 clk_divisor; - tegra_i2c_clock_enable(i2c_dev); + err = tegra_i2c_clock_enable(i2c_dev); + if (err < 0) { + dev_err(i2c_dev->dev, "Clock enable failed %d\n", err); + return err; + } tegra_periph_reset_assert(i2c_dev->div_clk); udelay(2); @@ -628,7 +632,12 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], if (i2c_dev->is_suspended) return -EBUSY; - tegra_i2c_clock_enable(i2c_dev); + ret = tegra_i2c_clock_enable(i2c_dev); + if (ret < 0) { + dev_err(i2c_dev->dev, "Clock enable failed %d\n", ret); + return ret; + } + for (i = 0; i < num; i++) { enum msg_end_type end_type = MSG_END_STOP; if (i < (num - 1)) { -- 1.7.1.1