Re: [PATCH 0/5] platform/x86: hp-wmi: fix bugs in Victus S fan control

[Krishna Chomal]

On Sat, Mar 21, 2026 at 02:55:52AM +0300, Emre Cecanpunar wrote:
> This series fixes five bugs in the hwmon fan control code added for
> HP Victus S laptops:
>
> - Return values from WMI calls were silently discarded in two paths
>  of hp_wmi_apply_fan_settings(), and the function's own return value
>  was ignored by both of its callers.
> - cancel_delayed_work_sync() was called from inside the work handler
>  it was trying to cancel, causing a potential deadlock.
> - schedule_delayed_work() does not reset a pending timer, so rapid
>  back-to-back fan updates did not extend the keep-alive window.
> - u8 arithmetic was used to compute a signed delta, producing silent
>  unsigned wrap-around on malformed firmware fan tables.
> - mode and pwm fields in hp_wmi_hwmon_priv were accessed from both
>  sysfs and workqueue context without any synchronisation.
>
> Patches are ordered so that each one applies cleanly on top of the
> previous. Patches 1-4 are independent fixes; patch 5 (locking) builds
> on patch 2 (cancel_delayed_work) to avoid a lock-ordering issue.
>
> Emre Cecanpunar (5):
>  platform/x86: hp-wmi: fix ignored return values in fan settings
>  platform/x86: hp-wmi: avoid cancel_delayed_work_sync from work handler
>  platform/x86: hp-wmi: use mod_delayed_work to reset keep-alive timer
>  platform/x86: hp-wmi: fix u8 underflow in gpu_delta calculation
>  platform/x86: hp-wmi: add locking for concurrent hwmon access
>
> drivers/platform/x86/hp/hp-wmi.c | 59 ++++++++++++++++++++++----------
> 1 file changed, 41 insertions(+), 18 deletions(-)
>
> --
> 2.53.0

Hi Emre,

Thank you for reviewing and catching these bugs. As this was my first
attempt with delayed workqueues, I appreciate the bug fixes, specially
regarding the deadlock.

I have tested this series on my hardware (board ID: 8C78) and can
confirm that the fans still behave correctly with the improvements.