Re: [PATCH v2] hwmon: (gpio-fan) fix pm_runtime imbalance for alarm-only fans
From: Guenter Roeck
Date: Sun Aug 30 2026 - 11:22:27 EST
On 8/30/26 08:05, Cong Nguyen wrote:
pm_runtime_enable() runs unconditionally in probe, but the devm cleanup
that calls pm_runtime_disable() is only registered when control GPIOs
are present. Alarm-only fans never get it, so unbind warns about the
missing disable.
Switch to devm_pm_runtime_enable(), registered before gpio_fan_stop()'s
devm action so LIFO teardown runs gpio_fan_stop() first. gpio_fan_stop()
calls set_fan_speed(0) -> pm_runtime_put_sync(), which needs PM still
enabled to reach gpio_fan_runtime_suspend() and turn the regulator off;
registering enable after gpio_fan_stop() (as v1 did) reverses that order
and leaves the regulator on.
Fixes: 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/b9792be3-fcd6-468c-9149-7e33640ee167@xxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <congnt264@xxxxxxxxx>
---
Another instance of a new patch version sent as reply to a previous
version.
It is against guidance in Documentation/process/submitting-patches.rst,
yet it proliferates, and more and more people send new patch revisions
this way. Where is this suggested ?
Thanks,
Guenter