commit: 132c803f7b70b17322579f6f4f3f65cf68e55135 From: Laxman Dewangan <[email protected]> Date: Fri, 15 Mar 2013 05:34:08 +0000 Subject: 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 <[email protected]> Reviewed-by: Stephen Warren <[email protected]> Signed-off-by: Wolfram Sang <[email protected]> Cc: [email protected] --- 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 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)) { -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
