diff options
| author | Emre Cecanpunar <emreleno@gmail.com> | 2026-04-07 17:25:14 +0300 |
|---|---|---|
| committer | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2026-04-09 14:46:36 +0300 |
| commit | 5969c55e2145368254194edbe0e64880314be69f (patch) | |
| tree | 411948b1376a0011d596c52d2f2ef5126dae5b5d | |
| parent | cb4daa450f05447c1f914eaef75b2577c25a0fcd (diff) | |
| download | linux-5969c55e2145368254194edbe0e64880314be69f.tar.xz | |
platform/x86: hp-wmi: add locking for concurrent hwmon access
hp_wmi_hwmon_priv.mode and .pwm are written by hp_wmi_hwmon_write() in
sysfs context and read by hp_wmi_hwmon_keep_alive_handler() in a
workqueue. A concurrent write and keep-alive expiry can observe an
inconsistent mode/pwm pair (e.g. mode=MANUAL with a stale pwm).
Add a mutex to hp_wmi_hwmon_priv protecting mode and pwm. Hold it in
hp_wmi_hwmon_write() across the field update and apply call, and in
hp_wmi_hwmon_keep_alive_handler() before calling apply.
In hp_wmi_hwmon_read(), only the pwm_enable path reads priv->mode; use
scoped_guard() there to avoid holding the lock across unrelated WMI
calls.
Fixes: c203c59fb5de ("platform/x86: hp-wmi: implement fan keep-alive")
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Emre Cecanpunar <emreleno@gmail.com>
Link: https://patch.msgid.link/20260407142515.20683-6-emreleno@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
| -rw-r--r-- | drivers/platform/x86/hp/hp-wmi.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c index 4f49861d3fbe..470c6e48f8e9 100644 --- a/drivers/platform/x86/hp/hp-wmi.c +++ b/drivers/platform/x86/hp/hp-wmi.c @@ -453,6 +453,7 @@ enum pwm_modes { }; struct hp_wmi_hwmon_priv { + struct mutex lock; /* protects mode, pwm */ u8 min_rpm; u8 max_rpm; int gpu_delta; @@ -2422,6 +2423,7 @@ static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, { struct hp_wmi_hwmon_priv *priv; int rpm, ret; + u8 mode; priv = dev_get_drvdata(dev); switch (type) { @@ -2445,11 +2447,13 @@ static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, *val = rpm_to_pwm(rpm / 100, priv); return 0; } - switch (priv->mode) { + scoped_guard(mutex, &priv->lock) + mode = priv->mode; + switch (mode) { case PWM_MODE_MAX: case PWM_MODE_MANUAL: case PWM_MODE_AUTO: - *val = priv->mode; + *val = mode; return 0; default: /* shouldn't happen */ @@ -2467,6 +2471,7 @@ static int hp_wmi_hwmon_write(struct device *dev, enum hwmon_sensor_types type, int rpm; priv = dev_get_drvdata(dev); + guard(mutex)(&priv->lock); switch (type) { case hwmon_pwm: if (attr == hwmon_pwm_input) { @@ -2535,6 +2540,8 @@ static void hp_wmi_hwmon_keep_alive_handler(struct work_struct *work) dwork = to_delayed_work(work); priv = container_of(dwork, struct hp_wmi_hwmon_priv, keep_alive_dwork); + + guard(mutex)(&priv->lock); /* * Re-apply the current hwmon context settings. * NOTE: hp_wmi_apply_fan_settings will handle the re-scheduling. @@ -2591,6 +2598,10 @@ static int hp_wmi_hwmon_init(void) if (!priv) return -ENOMEM; + ret = devm_mutex_init(dev, &priv->lock); + if (ret) + return ret; + ret = hp_wmi_setup_fan_settings(priv); if (ret) return ret; |