From 132c803f7b70b17322579f6f4f3f65cf68e55135 Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Fri, 15 Mar 2013 05:34:08 +0000 Subject: [PATCH] i2c: tegra: check the clk_prepare_enable() return value 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 Reviewed-by: Stephen Warren Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- drivers/i2c/busses/i2c-tegra.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 36704e3ab3fa..b714776b6ddd 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)) { -- 2.34.1