linux-kernel - Re: [PATCH v2 2/2] platform/x86: hp-wmi: implement fan keep-alive

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <6b2be55e-dcfe-74b7-d8ca-b78f49cedb7a@linux.intel.com>
Date: Mon, 12 Jan 2026 17:14:12 +0200 (EET)
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Krishna Chomal <krishna.chomal108@...il.com>
cc: Hans de Goede <hansg@...nel.org>, linux@...ck-us.net, 
    platform-driver-x86@...r.kernel.org, linux-hwmon@...r.kernel.org, 
    LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] platform/x86: hp-wmi: implement fan keep-alive

On Tue, 30 Dec 2025, Krishna Chomal wrote:

> The firmware on some HP laptops automatically reverts the fan speed
> control to "Auto" mode after a 120 second timeout window.
> 
> To ensure that the user-selected fan profile (Max/Manual) persists,
> implement a keep-alive mechanism that periodically refreshes the fan
> mode trigger before the timeout occurs.
> 
> - Introduce a delayed workqueue to trigger the fan mode refresh every 90
>   seconds, ensuring the system maintains the correct fan mode setting.
> - Integrate the refresh mechanism into hp_wmi_hwmon_enforce_ctx() to
>   start, update or cancel the keep-alive process based on the current
>   fan mode.
> 
> This ensures that the driver stays in sync with the hardware.
> 
> Tested on: HP Omen 16-wf1xxx (board ID 8C78)
> 
> Signed-off-by: Krishna Chomal <krishna.chomal108@...il.com>
> ---
> Changes in v2:
> - Explicitly specify time unit in KEEP_ALIVE_DELAY macro
> - Handle work rescheduling directly in switch/case
> ---
>  drivers/platform/x86/hp/hp-wmi.c | 46 +++++++++++++++++++++++++++++---
>  1 file changed, 43 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index ef419575174c..cf9327e1f40e 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -34,6 +34,7 @@
>  #include <linux/limits.h>
>  #include <linux/minmax.h>
>  #include <linux/compiler_attributes.h>
> +#include <linux/workqueue.h>
>  
>  MODULE_AUTHOR("Matthew Garrett <mjg59@...f.ucam.org>");
>  MODULE_DESCRIPTION("HP laptop WMI driver");
> @@ -368,6 +369,7 @@ struct hp_wmi_hwmon_priv {
>  	u8 gpu_delta;
>  	u8 mode;
>  	u8 pwm;
> +	struct delayed_work keep_alive_dwork;
>  };
>  
>  struct victus_s_fan_table_header {
> @@ -386,6 +388,12 @@ struct victus_s_fan_table {
>  	struct victus_s_fan_table_entry entries[];
>  } __packed;
>  
> +/*
> + * 90s delay to prevent the firmware from resetting fan mode after fixed
> + * 120s timeout
> + */
> +#define KEEP_ALIVE_DELAY_SECS     90
> +
>  static inline u8 rpm_to_pwm(u8 rpm, struct hp_wmi_hwmon_priv *priv)
>  {
>  	return fixp_linear_interpolate(0, 0, priv->max_rpm, U8_MAX,
> @@ -2093,6 +2101,7 @@ static int __init hp_wmi_bios_setup(struct platform_device *device)
>  static void __exit hp_wmi_bios_remove(struct platform_device *device)
>  {
>  	int i;
> +	struct hp_wmi_hwmon_priv *ctx;

Can't we just call this priv everywhere as per the normal custom?

>  
>  	for (i = 0; i < rfkill2_count; i++) {
>  		rfkill_unregister(rfkill2[i].rfkill);
> @@ -2111,6 +2120,10 @@ static void __exit hp_wmi_bios_remove(struct platform_device *device)
>  		rfkill_unregister(wwan_rfkill);
>  		rfkill_destroy(wwan_rfkill);
>  	}
> +
> +	ctx = platform_get_drvdata(device);
> +	if (ctx)
> +		cancel_delayed_work_sync(&ctx->keep_alive_dwork);
>  }
>  
>  static int hp_wmi_resume_handler(struct device *device)
> @@ -2179,12 +2192,20 @@ static int hp_wmi_apply_fan_settings(struct hp_wmi_hwmon_priv *priv)
>  		if (is_victus_s_thermal_profile())
>  			hp_wmi_get_fan_count_userdefine_trigger();
>  		ret = hp_wmi_fan_speed_max_set(1);
> -		return ret;
> +		if (ret < 0)
> +			return ret;
> +		schedule_delayed_work(&priv->keep_alive_dwork,
> +				      secs_to_jiffies(KEEP_ALIVE_DELAY_SECS));
> +		return 0;
>  	case PWM_MODE_MANUAL:
>  		if (!is_victus_s_thermal_profile())
>  			return -EOPNOTSUPP;
>  		ret = hp_wmi_fan_speed_set(priv, pwm_to_rpm(priv->pwm, priv));
> -		return ret;
> +		if (ret < 0)
> +			return ret;
> +		schedule_delayed_work(&priv->keep_alive_dwork,
> +				      secs_to_jiffies(KEEP_ALIVE_DELAY_SECS));
> +		return 0;
>  	case PWM_MODE_AUTO:
>  		if (is_victus_s_thermal_profile()) {
>  			hp_wmi_get_fan_count_userdefine_trigger();
> @@ -2192,7 +2213,10 @@ static int hp_wmi_apply_fan_settings(struct hp_wmi_hwmon_priv *priv)
>  		} else {
>  			ret = hp_wmi_fan_speed_max_set(0);
>  		}
> -		return ret;
> +		if (ret < 0)
> +			return ret;
> +		cancel_delayed_work_sync(&priv->keep_alive_dwork);
> +		return 0;
>  	default:
>  		/* shouldn't happen */
>  		return -EINVAL;
> @@ -2337,6 +2361,20 @@ static const struct hwmon_chip_info chip_info = {
>  	.info = info,
>  };
>  
> +static void hp_wmi_hwmon_keep_alive_handler(struct work_struct *work)
> +{
> +	struct delayed_work *dwork;
> +	struct hp_wmi_hwmon_priv *ctx;
> +
> +	dwork = to_delayed_work(work);
> +	ctx = container_of(dwork, struct hp_wmi_hwmon_priv, keep_alive_dwork);
> +	/*
> +	 * Re-apply the current hwmon context settings.
> +	 * NOTE: hp_wmi_apply_fan_settings will handle the re-scheduling.
> +	 */
> +	hp_wmi_apply_fan_settings(ctx);
> +}
> +
>  static int hp_wmi_setup_fan_settings(struct hp_wmi_hwmon_priv *priv)
>  {
>  	u8 fan_data[128] = { 0 };
> @@ -2395,6 +2433,8 @@ static int hp_wmi_hwmon_init(void)
>  		return PTR_ERR(hwmon);
>  	}
>  
> +	INIT_DELAYED_WORK(&priv->keep_alive_dwork, hp_wmi_hwmon_keep_alive_handler);
> +	platform_set_drvdata(hp_wmi_platform_dev, priv);
>  	hp_wmi_apply_fan_settings(priv);
>  
>  	return 0;
> 

-- 
 i.