Re: [PATCH togreg v3 1/2] iio: imu: inv_icm42607: propagate runtime suspend errors

[Linmao Li]

在 2026/8/16 4:52, Jonathan Cameron 写道:
> On Tue, 11 Aug 2026 18:33:00 +0800
> Linmao Li <lilinmao@xxxxxxxxxx> wrote:
>
> > The runtime suspend callback always returns success even when updating
> > PWR_MGMT0 fails. The PM core can then mark the device suspended while one
> > or both sensors remain enabled.
> >
> > The sibling ICM-42600 driver propagates the corresponding
> > inv_icm42600_set_pwr_mgmt0() failure from its runtime suspend callback.
> > Make ICM-42607 follow the same behavior by returning the sensor shutdown
> > error. Keep a void wrapper for the managed teardown action, where errors
> > can only be logged.
> What is the practical affect of a sensor remaining enabled?  Bit of
> power loss or something more significant?  This info matter when deciding
> if we should rush this in during the rc phase, or wait for the next
> merge window.
As far as I can tell, the practical effect is additional power
consumption while the device is idle.  I found no corruption path, but I
have no ICM-42607 hardware to reproduce the failure or measure the
current.

It does not necessarily persist indefinitely.  If the PWR_MGMT0 write
fails, regmap may contain the requested OFF state while the hardware
remains ON.  A later sensor read requests an enabled mode, so
inv_icm42607_set_pwr_mgmt0() retries the write instead of taking its
"no change" return.  If the bus error was transient, the cache and
hardware are then resynchronized.

I also noticed a cost to this patch: returning an error such as -EIO from
.runtime_suspend() makes the PM core set power.runtime_error. Subsequent
reads then fail in PM_RUNTIME_ACQUIRE_AUTOSUSPEND() before any sensor
register is accessed, until the PM status is reset.  A successful system
suspend may clear that state.

The patch therefore trades a logged idle power leak that may recover on
a later access for a potentially sticky runtime-PM failure.  Since this
was found by inspection only, I would not rush it into the rc phase.  I
would rather revisit the error handling and target the next merge window.

Linmao

> Jonathan
>
>
> > Fixes: 3007c1530f96 ("iio: imu: inv_icm42607: Add PM support for icm42607")
> > Signed-off-by: Linmao Li <lilinmao@xxxxxxxxxx>
> > ---
> > Unchanged since v1.
> >
> >   drivers/iio/imu/inv_icm42607/inv_icm42607_core.c | 15 ++++++++++-----
> >   1 file changed, 10 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> > index 190e998f7b8ef..0da362967f63b 100644
> > --- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> > +++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> > @@ -537,9 +537,8 @@ static int inv_icm42607_enable_vddio_reg(struct inv_icm42607_state *st)
> >   	return 0;
> >   }
> >   
> > -static void inv_icm42607_sensors_off(void *_data)
> > +static int inv_icm42607_sensors_off(struct inv_icm42607_state *st)
> >   {
> > -	struct inv_icm42607_state *st = _data;
> >   	const struct device *dev = regmap_get_device(st->map);
> >   	int ret;
> >   
> > @@ -552,6 +551,13 @@ static void inv_icm42607_sensors_off(void *_data)
> >   					 st->conf.accel.mode);
> >   	if (ret)
> >   		dev_err(dev, "Unable to turn off sensors\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static void inv_icm42607_sensors_off_action(void *data)
> > +{
> > +	inv_icm42607_sensors_off(data);
> >   }
> >   
> >   static void inv_icm42607_disable_vddio_reg(void *_data)
> > @@ -619,7 +625,7 @@ int inv_icm42607_core_probe(struct regmap *regmap,
> >   	 * Ensure if sensors get turned on at some point, they're turned off
> >   	 * as part of teardown.
> >   	 */
> > -	ret = devm_add_action_or_reset(dev, inv_icm42607_sensors_off, st);
> > +	ret = devm_add_action_or_reset(dev, inv_icm42607_sensors_off_action, st);
> >   	if (ret)
> >   		return ret;
> >   
> > @@ -688,8 +694,7 @@ static int inv_icm42607_runtime_suspend(struct device *dev)
> >   	 * however the tradeoff is that an unused sensor won't be
> >   	 * turned off until the entire chip is no longer in use.
> >   	 */
> > -	inv_icm42607_sensors_off(st);
> > -	return 0;
> > +	return inv_icm42607_sensors_off(st);
> >   }
> >   
> >   EXPORT_NS_GPL_DEV_PM_OPS(inv_icm42607_pm_ops, IIO_ICM42607) = {