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Message-ID: <7072d96f-455a-5249-2553-6e72e6a00577@linux.intel.com>
Date: Mon, 29 Dec 2025 15:21:42 +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 2/2] platform/x86: hp-wmi: implement fan keep-alive
On Thu, 25 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>
> ---
> drivers/platform/x86/hp/hp-wmi.c | 52 +++++++++++++++++++++++++++++---
> 1 file changed, 48 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
> index 9fb956ce809a..fbe012e7a342 100644
> --- a/drivers/platform/x86/hp/hp-wmi.c
> +++ b/drivers/platform/x86/hp/hp-wmi.c
> @@ -31,6 +31,7 @@
> #include <linux/string.h>
> #include <linux/dmi.h>
> #include <linux/fixp-arith.h>
> +#include <linux/workqueue.h>
>
> MODULE_AUTHOR("Matthew Garrett <mjg59@...f.ucam.org>");
> MODULE_DESCRIPTION("HP laptop WMI driver");
> @@ -365,8 +366,15 @@ struct hp_wmi_hwmon_priv {
> u8 gpu_delta;
> u8 mode;
> u8 pwm;
> + struct delayed_work keep_alive_dwork;
> };
>
> +/*
> + * 90s delay to prevent the firmware from resetting fan mode after fixed
> + * 120s timeout
> + */
> +#define KEEP_ALIVE_DELAY 90
For any time related define, please include its unit in the name so a
person reading code can immediately know it.
> +
> #define RPM_TO_PWM(rpm, ctx) fixp_linear_interpolate(0, 0, \
> (ctx)->max_rpm, U8_MAX, \
> clamp_val((rpm), \
> @@ -2073,6 +2081,7 @@ 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;
>
> for (i = 0; i < rfkill2_count; i++) {
> rfkill_unregister(rfkill2[i].rfkill);
> @@ -2091,6 +2100,10 @@ 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)
> @@ -2152,6 +2165,8 @@ static struct platform_driver hp_wmi_driver __refdata = {
>
> static int hp_wmi_hwmon_enforce_ctx(struct hp_wmi_hwmon_priv *ctx)
> {
> + int ret;
> +
> if (!ctx)
> return -ENODEV;
>
> @@ -2159,23 +2174,36 @@ static int hp_wmi_hwmon_enforce_ctx(struct hp_wmi_hwmon_priv *ctx)
> case PWM_MODE_MAX:
> if (is_victus_s_thermal_profile())
> hp_wmi_get_fan_count_userdefine_trigger();
> - return hp_wmi_fan_speed_max_set(1);
> + ret = hp_wmi_fan_speed_max_set(1);
> + break;
> case PWM_MODE_MANUAL:
> if (!is_victus_s_thermal_profile())
> return -EOPNOTSUPP;
> - return hp_wmi_fan_speed_set(ctx, PWM_TO_RPM(ctx->pwm, ctx));
> + ret = hp_wmi_fan_speed_set(ctx, PWM_TO_RPM(ctx->pwm, ctx));
> + break;
> case PWM_MODE_AUTO:
> if (is_victus_s_thermal_profile()) {
> hp_wmi_get_fan_count_userdefine_trigger();
> - return hp_wmi_fan_speed_max_reset(ctx);
> + ret = hp_wmi_fan_speed_max_reset(ctx);
> } else {
> - return hp_wmi_fan_speed_max_set(0);
> + ret = hp_wmi_fan_speed_max_set(0);
> }
> + break;
> default:
> /* shouldn't happen */
> return -EINVAL;
> }
>
> + if (ret < 0)
> + return ret;
> +
> + /* Reschedule keep-alive work based on the new state */
> + if (ctx->mode == PWM_MODE_MAX || ctx->mode == PWM_MODE_MANUAL)
> + schedule_delayed_work(&ctx->keep_alive_dwork,
> + secs_to_jiffies(KEEP_ALIVE_DELAY));
> + else
> + cancel_delayed_work_sync(&ctx->keep_alive_dwork);
This is now duplicating the switch/case, just add these to the existing
cases.
You may want to introduce ret variable already in PATCH 1/2 and add a note
there that an upcoming change is going to add keep-alive so the return
value has to be stored temporarily.
> +
> return 0;
> }
>
> @@ -2321,6 +2349,20 @@ 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_hwmon_enforce_ctx will handle the re-scheduling.
> + */
> + hp_wmi_hwmon_enforce_ctx(ctx);
(I only now understand why you named this function like this, and I still
don't think it's a good name for it as you've other callers besides this
one real "enforcing" case.)
> +}
> +
> static int hp_wmi_hwmon_setup_ctx(struct hp_wmi_hwmon_priv *ctx)
> {
> u8 fan_data[128];
> @@ -2377,6 +2419,8 @@ static int hp_wmi_hwmon_init(void)
> return PTR_ERR(hwmon);
> }
>
> + INIT_DELAYED_WORK(&ctx->keep_alive_dwork, hp_wmi_hwmon_keep_alive_handler);
> + platform_set_drvdata(hp_wmi_platform_dev, ctx);
> hp_wmi_hwmon_enforce_ctx(ctx);
>
> return 0;
>
--
i.
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