[PATCH v3 08/11] platform/x86: asus-wmi: Enhance detection of thermal data

From: Yurii Pavlovskyi
Date: Fri Apr 19 2019 - 15:24:14 EST


The obviously wrong value 1 for temperature device ID in this driver is
returned by at least some devices, including TUF Gaming series laptops,
instead of 0 as expected previously. Observable effect is that a
temp1_input in hwmon reads temperature near absolute zero.

* Consider 0.1 K an erroneous value in addition to 0 K.
* Refactor detection of thermal input availability to a separate function.

Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@xxxxxxxxx>
---
drivers/platform/x86/asus-wmi.c | 45 ++++++++++++++++++++++++++++-----
1 file changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index e69e55635afb..1b8272374660 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -178,6 +178,7 @@ struct asus_wmi {
struct asus_rfkill gps;
struct asus_rfkill uwb;

+ bool asus_hwmon_thermal_available;
bool asus_hwmon_fan_manual_mode;
int asus_hwmon_num_fans;
int asus_hwmon_pwm;
@@ -1375,6 +1376,32 @@ static struct attribute *hwmon_attributes[] = {
NULL
};

+static int asus_hwmon_check_thermal_available(struct asus_wmi *asus)
+{
+ u32 value = ASUS_WMI_UNSUPPORTED_METHOD;
+ int err;
+
+ asus->asus_hwmon_thermal_available = false;
+ err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_THERMAL_CTRL, &value);
+
+ if (err < 0) {
+ if (err == -ENODEV)
+ return 0;
+
+ return err;
+ }
+
+ /*
+ * If the temperature value in deci-Kelvin is near the absolute
+ * zero temperature, something is clearly wrong.
+ */
+ if (!value || value == 1)
+ return 0;
+
+ asus->asus_hwmon_thermal_available = true;
+ return 0;
+}
+
static umode_t asus_hwmon_sysfs_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
@@ -1388,8 +1415,6 @@ static umode_t asus_hwmon_sysfs_is_visible(struct kobject *kobj,

if (attr == &dev_attr_pwm1.attr)
dev_id = ASUS_WMI_DEVID_FAN_CTRL;
- else if (attr == &dev_attr_temp1_input.attr)
- dev_id = ASUS_WMI_DEVID_THERMAL_CTRL;

if (attr == &dev_attr_fan1_input.attr
|| attr == &dev_attr_fan1_label.attr
@@ -1414,15 +1439,13 @@ static umode_t asus_hwmon_sysfs_is_visible(struct kobject *kobj,
* - reverved bits are non-zero
* - sfun and presence bit are not set
*/
- if (value == ASUS_WMI_UNSUPPORTED_METHOD || value & 0xFFF80000
+ if (value == ASUS_WMI_UNSUPPORTED_METHOD || (value & 0xFFF80000)
|| (!asus->sfun && !(value & ASUS_WMI_DSTS_PRESENCE_BIT)))
ok = false;
else
ok = fan_attr <= asus->asus_hwmon_num_fans;
- } else if (dev_id == ASUS_WMI_DEVID_THERMAL_CTRL) {
- /* If value is zero, something is clearly wrong */
- if (!value)
- ok = false;
+ } else if (attr == &dev_attr_temp1_input.attr) {
+ ok = asus->asus_hwmon_thermal_available;
} else if (fan_attr <= asus->asus_hwmon_num_fans && fan_attr != -1) {
ok = true;
} else {
@@ -1469,6 +1492,14 @@ static int asus_wmi_fan_init(struct asus_wmi *asus)
}

pr_info("Number of fans: %d\n", asus->asus_hwmon_num_fans);
+
+ status = asus_hwmon_check_thermal_available(asus);
+ if (status) {
+ pr_warn("Could not check if thermal available: %d\n", status);
+ return -ENXIO;
+ }
+
+ pr_info("Thermal available: %d\n", asus->asus_hwmon_thermal_available);
return 0;
}

--
2.17.1