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
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 @@
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 @@
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)) {