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authorLaxman Dewangan <ldewangan@nvidia.com>2013-03-15 05:34:08 +0000
committerWolfram Sang <wsa@the-dreams.de>2013-03-22 10:28:55 +0100
commit132c803f7b70b17322579f6f4f3f65cf68e55135 (patch)
treebb819b313733035c821a9984ded83e3dc2a1f6d8 /drivers/i2c/busses
parenta937536b868b8369b98967929045f1df54234323 (diff)
downloadvexpress-lsk-132c803f7b70b17322579f6f4f3f65cf68e55135.tar.gz
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 <ldewangan@nvidia.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r--drivers/i2c/busses/i2c-tegra.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 36704e3ab3f..b714776b6dd 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)) {