From: Emre Cecanpunar Date: Tue, 7 Apr 2026 14:25:13 +0000 (+0300) Subject: platform/x86: hp-wmi: fix u8 underflow in gpu_delta calculation X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=cb4daa450f05447c1f914eaef75b2577c25a0fcd;p=thirdparty%2Fkernel%2Flinux.git platform/x86: hp-wmi: fix u8 underflow in gpu_delta calculation gpu_delta was declared as u8. If the firmware specifies a GPU RPM lower than the CPU RPM, subtracting them causes an underflow (e.g. 10 - 20 = 246), which forces the GPU fan to remain clamped at U8_MAX (100% speed) during operation. Change gpu_delta to int and use signed arithmetic. Existing signed logic in hp_wmi_fan_speed_set() correctly handles negative deltas. Fixes: 46be1453e6e6 ("platform/x86: hp-wmi: add manual fan control for Victus S models") Suggested-by: Ilpo Järvinen Signed-off-by: Emre Cecanpunar Link: https://patch.msgid.link/20260407142515.20683-5-emreleno@gmail.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c index 2932cab9aa78..4f49861d3fbe 100644 --- a/drivers/platform/x86/hp/hp-wmi.c +++ b/drivers/platform/x86/hp/hp-wmi.c @@ -455,7 +455,7 @@ enum pwm_modes { struct hp_wmi_hwmon_priv { u8 min_rpm; u8 max_rpm; - u8 gpu_delta; + int gpu_delta; u8 mode; u8 pwm; struct delayed_work keep_alive_dwork; @@ -2549,8 +2549,8 @@ static int hp_wmi_setup_fan_settings(struct hp_wmi_hwmon_priv *priv) { u8 fan_data[128] = { 0 }; struct victus_s_fan_table *fan_table; - u8 min_rpm, max_rpm, gpu_delta; - int ret; + u8 min_rpm, max_rpm; + int gpu_delta, ret; /* Default behaviour on hwmon init is automatic mode */ priv->mode = PWM_MODE_AUTO;