Re: Re: Re: [PATCH] iio: magnetometer: ak8974: Fix runtime PM imbalance on error
> What about just moving the pm_runtime_put() until the end > of the initialization? Right before return 0; > Then we can keep this nice goto exits as they are. > > Maybe move all these three: > > pm_runtime_set_autosuspend_delay(>dev, > AK8974_AUTOSUSPEND_DELAY); > pm_runtime_use_autosuspend(>dev); > pm_runtime_put(>dev); > Good idea! Thank you for your advice and I will fix this in the next version of patch. Regards, Dinghao
Re: Re: [PATCH] iio: magnetometer: ak8974: Fix runtime PM imbalance on error
On Tue, May 26, 2020 at 7:14 AM wrote: > > On Sun, May 24, 2020 at 4:51 AM Dinghao Liu wrote: > > > disable_pm: > > > - pm_runtime_put_noidle(>dev); > > > pm_runtime_disable(>dev); > > > ak8974_set_power(ak8974, AK8974_PWR_OFF); > > > > Keep the top pm_runtime_put_noidle(). > > I found that there was already a pm_runtime_put() before > iio_triggered_buffer_setup() (just after pm_runtime_use_autosuspend). > So if we keep the pm_runtime_put_noidle() here, we will have > two pmusage counter decrement. Do you think this is a bug? Yes you're right. What about just moving the pm_runtime_put() until the end of the initialization? Right before return 0; Then we can keep this nice goto exits as they are. Maybe move all these three: pm_runtime_set_autosuspend_delay(>dev, AK8974_AUTOSUSPEND_DELAY); pm_runtime_use_autosuspend(>dev); pm_runtime_put(>dev); Yours, Linus Walleij
Re: Re: [PATCH] iio: magnetometer: ak8974: Fix runtime PM imbalance on error
Hi, Linus
> On Sun, May 24, 2020 at 4:51 AM Dinghao Liu 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
>
> > ak8974->map = devm_regmap_init_i2c(i2c, _regmap_config);
> > if (IS_ERR(ak8974->map)) {
> > dev_err(>dev, "failed to allocate register map\n");
> > + pm_runtime_put_noidle(>dev);
> > + pm_runtime_disable(>dev);
> > return PTR_ERR(ak8974->map);
>
> This is correct.
>
> > ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
> > if (ret) {
> > dev_err(>dev, "could not power on\n");
> > + pm_runtime_put_noidle(>dev);
> > + pm_runtime_disable(>dev);
> > goto power_off;
>
> What about just changing this to goto disable_pm;
>
> > ret = ak8974_detect(ak8974);
> > if (ret) {
> > dev_err(>dev, "neither AK8974 nor AMI30x found\n");
> > + pm_runtime_put_noidle(>dev);
> > + pm_runtime_disable(>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(>dev, "AK8974 reset failed\n");
> > + pm_runtime_put_noidle(>dev);
> > + pm_runtime_disable(>dev);
>
> goto disable_pm;
>
> > disable_pm:
> > - pm_runtime_put_noidle(>dev);
> > pm_runtime_disable(>dev);
> > ak8974_set_power(ak8974, AK8974_PWR_OFF);
>
> Keep the top pm_runtime_put_noidle().
I found that there was already a pm_runtime_put() before
iio_triggered_buffer_setup() (just after pm_runtime_use_autosuspend).
So if we keep the pm_runtime_put_noidle() here, we will have
two pmusage counter decrement. Do you think this is a bug?
Regards,
Dinghao
>
> 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
Re: [PATCH] iio: magnetometer: ak8974: Fix runtime PM imbalance on error
On Sun, May 24, 2020 at 4:51 AM Dinghao Liu 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
> ak8974->map = devm_regmap_init_i2c(i2c, _regmap_config);
> if (IS_ERR(ak8974->map)) {
> dev_err(>dev, "failed to allocate register map\n");
> + pm_runtime_put_noidle(>dev);
> + pm_runtime_disable(>dev);
> return PTR_ERR(ak8974->map);
This is correct.
> ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
> if (ret) {
> dev_err(>dev, "could not power on\n");
> + pm_runtime_put_noidle(>dev);
> + pm_runtime_disable(>dev);
> goto power_off;
What about just changing this to goto disable_pm;
> ret = ak8974_detect(ak8974);
> if (ret) {
> dev_err(>dev, "neither AK8974 nor AMI30x found\n");
> + pm_runtime_put_noidle(>dev);
> + pm_runtime_disable(>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(>dev, "AK8974 reset failed\n");
> + pm_runtime_put_noidle(>dev);
> + pm_runtime_disable(>dev);
goto disable_pm;
> disable_pm:
> - pm_runtime_put_noidle(>dev);
> pm_runtime_disable(>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
