On Sun, May 24, 2020 at 4:51 AM Dinghao Liu <dinghao.liu@xxxxxxxxxx> wrote:
> When devm_regmap_init_i2c() returns an error code, a pairing
> runtime PM usage counter decrement is needed to keep the
> counter balanced. For error paths after ak8974_set_power(),
> ak8974_detect() and ak8974_reset(), things are the same.
>
> However, When iio_triggered_buffer_setup() returns an error
> code, we don't need such a decrement because there is already
> one before this call. Things are the same for other error paths
> after it.
>
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
> if (IS_ERR(ak8974->map)) {
> dev_err(&i2c->dev, "failed to allocate register map\n");
> + pm_runtime_put_noidle(&i2c->dev);
> + pm_runtime_disable(&i2c->dev);
> return PTR_ERR(ak8974->map);
This is correct.
> ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
> if (ret) {
> dev_err(&i2c->dev, "could not power on\n");
> + pm_runtime_put_noidle(&i2c->dev);
> + pm_runtime_disable(&i2c->dev);
> goto power_off;
What about just changing this to goto disable_pm;
> ret = ak8974_detect(ak8974);
> if (ret) {
> dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
> + pm_runtime_put_noidle(&i2c->dev);
> + pm_runtime_disable(&i2c->dev);
> goto power_off;
goto disable_pm;
> @@ -786,6 +792,8 @@ static int ak8974_probe(struct i2c_client *i2c,
> ret = ak8974_reset(ak8974);
> if (ret) {
> dev_err(&i2c->dev, "AK8974 reset failed\n");
> + pm_runtime_put_noidle(&i2c->dev);
> + pm_runtime_disable(&i2c->dev);
goto disable_pm;
> disable_pm:
> - pm_runtime_put_noidle(&i2c->dev);
> pm_runtime_disable(&i2c->dev);
> ak8974_set_power(ak8974, AK8974_PWR_OFF);
Keep the top pm_runtime_put_noidle().
The ak8974_set_power() call is fine, the power on call does not
need to happen in balance. Sure it will attempt to write a register
but so will the power on call.
Yours,
Linus Walleij
