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

在 2026/8/16 4:52, Jonathan Cameron 写道:
> On Tue, 11 Aug 2026 18:33:00 +0800
> Linmao Li <[email protected]> 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 <[email protected]>
>> ---
>> 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) = {