From 830e0bef79aaaea8b1ef426b8032e70c63a58653 Mon Sep 17 00:00:00 2001 From: "leobannocloutier@gmail.com" Date: Fri, 16 Jan 2026 20:53:15 -0500 Subject: hwmon: (dell-smm) Add Dell G15 5510 to fan control whitelist On the Dell G15 5510, fans spin at maximum speed when AC power is connected. This behavior has been observed as a regression in recent kernels (v6.18+). Add the Dell G15 5510 to the fan control whitelist to enable manual fan control and resolve the issue. This model requires the same fan control configuration as the Dell G15 5511. Fixes: 1c1658058c99 ("hwmon: (dell-smm) Add support for automatic fan mode") Signed-off-by: Leo Banno-Cloutier Link: https://lore.kernel.org/r/20260117015315.214569-2-leobannocloutier@gmail.com [groeck: Updated patch description to follow guidance] Signed-off-by: Guenter Roeck --- drivers/hwmon/dell-smm-hwmon.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index 6040a8940674..93143cfc157c 100644 --- a/drivers/hwmon/dell-smm-hwmon.c +++ b/drivers/hwmon/dell-smm-hwmon.c @@ -1639,6 +1639,14 @@ static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = { }, .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_30A3_31A3], }, + { + .ident = "Dell G15 5510", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell G15 5510"), + }, + .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_30A3_31A3], + }, { .ident = "Dell G15 5511", .matches = { -- cgit v1.2.3 From 615901b57b7ef8eb655f71358f7e956e42bcd16b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 31 Jan 2026 07:23:28 -0800 Subject: hwmon: (acpi_power_meter) Fix deadlocks related to acpi_power_meter_notify() The acpi_power_meter driver's .notify() callback function, acpi_power_meter_notify(), calls hwmon_device_unregister() under a lock that is also acquired by callbacks in sysfs attributes of the device being unregistered which is prone to deadlocks between sysfs access and device removal. Address this by moving the hwmon device removal in acpi_power_meter_notify() outside the lock in question, but notice that doing it alone is not sufficient because two concurrent METER_NOTIFY_CONFIG notifications may be attempting to remove the same device at the same time. To prevent that from happening, add a new lock serializing the execution of the switch () statement in acpi_power_meter_notify(). For simplicity, it is a static mutex which should not be a problem from the performance perspective. The new lock also allows the hwmon_device_register_with_info() in acpi_power_meter_notify() to be called outside the inner lock because it prevents the other notifications handled by that function from manipulating the "resource" object while the hwmon device based on it is being registered. The sending of ACPI netlink messages from acpi_power_meter_notify() is serialized by the new lock too which generally helps to ensure that the order of handling firmware notifications is the same as the order of sending netlink messages related to them. In addition, notice that hwmon_device_register_with_info() may fail in which case resource->hwmon_dev will become an error pointer, so add checks to avoid attempting to unregister the hwmon device pointer to by it in that case to acpi_power_meter_notify() and acpi_power_meter_remove(). Fixes: 16746ce8adfe ("hwmon: (acpi_power_meter) Replace the deprecated hwmon_device_register") Closes: https://lore.kernel.org/linux-hwmon/CAK8fFZ58fidGUCHi5WFX0uoTPzveUUDzT=k=AAm4yWo3bAuCFg@mail.gmail.com/ Reported-by: Jaroslav Pulchart Signed-off-by: Rafael J. Wysocki Signed-off-by: Guenter Roeck --- drivers/hwmon/acpi_power_meter.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index 29ccdc2fb7ff..de408df0c4d7 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -47,6 +47,8 @@ static int cap_in_hardware; static bool force_cap_on; +static DEFINE_MUTEX(acpi_notify_lock); + static int can_cap_in_hardware(void) { return force_cap_on || cap_in_hardware; @@ -823,18 +825,26 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event) resource = acpi_driver_data(device); + guard(mutex)(&acpi_notify_lock); + switch (event) { case METER_NOTIFY_CONFIG: + if (!IS_ERR(resource->hwmon_dev)) + hwmon_device_unregister(resource->hwmon_dev); + mutex_lock(&resource->lock); + free_capabilities(resource); remove_domain_devices(resource); - hwmon_device_unregister(resource->hwmon_dev); res = read_capabilities(resource); if (res) dev_err_once(&device->dev, "read capabilities failed.\n"); res = read_domain_devices(resource); if (res && res != -ENODEV) dev_err_once(&device->dev, "read domain devices failed.\n"); + + mutex_unlock(&resource->lock); + resource->hwmon_dev = hwmon_device_register_with_info(&device->dev, ACPI_POWER_METER_NAME, @@ -843,7 +853,7 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event) power_extra_groups); if (IS_ERR(resource->hwmon_dev)) dev_err_once(&device->dev, "register hwmon device failed.\n"); - mutex_unlock(&resource->lock); + break; case METER_NOTIFY_TRIP: sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME); @@ -953,7 +963,8 @@ static void acpi_power_meter_remove(struct acpi_device *device) return; resource = acpi_driver_data(device); - hwmon_device_unregister(resource->hwmon_dev); + if (!IS_ERR(resource->hwmon_dev)) + hwmon_device_unregister(resource->hwmon_dev); remove_domain_devices(resource); free_capabilities(resource); -- cgit v1.2.3 From f5c092787c48296633c2dd7240752f88fa9710fc Mon Sep 17 00:00:00 2001 From: Gabor Juhos Date: Sun, 1 Feb 2026 21:35:06 +0100 Subject: hwmon: (gpio-fan) Fix set_rpm() return value The set_rpm function is used as a 'store' callback of a device attribute, and as such it should return with the number of bytes consumed. However since commit 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support"), the function returns with zero on success. Due to this, the function gets called again and again whenever the user tries to change the FAN speed by writing the desired RPM value into the 'fan1_target' sysfs attribute. The broken behaviour can be reproduced easily. For example, the following command never returns unless it gets terminated: $ echo 500 > /sys/class/hwmon/hwmon1/fan1_target ^C $ Change the code to return with the same value as the 'count' parameter on success to indicate that all bytes from the input buffer are consumed. The function behaved the same way prior to the offending change. Cc: stable@vger.kernel.org Fixes: 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support") Signed-off-by: Gabor Juhos Link: https://lore.kernel.org/r/20260201-gpio-fan-set_rpm-retval-fix-v1-1-dc39bc7693ca@gmail.com Signed-off-by: Guenter Roeck --- drivers/hwmon/gpio-fan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 516c34bb61c9..d7fa021f376e 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -291,7 +291,7 @@ static ssize_t set_rpm(struct device *dev, struct device_attribute *attr, { struct gpio_fan_data *fan_data = dev_get_drvdata(dev); unsigned long rpm; - int ret = count; + int ret; if (kstrtoul(buf, 10, &rpm)) return -EINVAL; @@ -308,7 +308,7 @@ static ssize_t set_rpm(struct device *dev, struct device_attribute *attr, exit_unlock: mutex_unlock(&fan_data->lock); - return ret; + return ret ? ret : count; } static DEVICE_ATTR_RW(pwm1); -- cgit v1.2.3 From 52fb36a5f9c15285b7d67c0ff87dc17b3206b5df Mon Sep 17 00:00:00 2001 From: Gabor Juhos Date: Mon, 2 Feb 2026 16:58:57 +0100 Subject: hwmon: (gpio-fan) Allow to stop FANs when CONFIG_PM is disabled When CONFIG_PM is disabled, the GPIO controlled FANs can't be stopped by using the sysfs attributes since commit 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support"). Using either the 'pwm1' or the 'fan1_target' attribute fails the same way: $ echo 0 > /sys/class/hwmon/hwmon1/pwm1 ash: write error: Function not implemented $ echo 0 > /sys/class/hwmon/hwmon1/fan1_target ash: write error: Function not implemented Both commands were working flawlessly before the mentioned commit. The issue happens because pm_runtime_put_sync() returns with -ENOSYS when CONFIG_PM is disabled, and the set_fan_speed() function handles this as an error. In order to restore the previous behaviour, change the error check in the set_fan_speed() function to ignore the -ENOSYS error code. Cc: stable@vger.kernel.org Fixes: 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support") Signed-off-by: Gabor Juhos Link: https://lore.kernel.org/r/20260202-gpio-fan-stop-fix-v1-1-c7853183d93d@gmail.com Signed-off-by: Guenter Roeck --- drivers/hwmon/gpio-fan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index d7fa021f376e..a8892ced1e54 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -148,7 +148,7 @@ static int set_fan_speed(struct gpio_fan_data *fan_data, int speed_index) int ret; ret = pm_runtime_put_sync(fan_data->dev); - if (ret < 0) + if (ret < 0 && ret != -ENOSYS) return ret; } -- cgit v1.2.3 From 831a2b27914cc880130ffe8fb8d1e65a5324d07f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 3 Feb 2026 17:34:36 +0100 Subject: hwmon: (occ) Mark occ_init_attribute() as __printf This is a printf-style function, which gcc -Werror=suggest-attribute=format correctly points out: drivers/hwmon/occ/common.c: In function 'occ_init_attribute': drivers/hwmon/occ/common.c:761:9: error: function 'occ_init_attribute' might be a candidate for 'gnu_printf' format attribute [-Werror=suggest-attribute=format] Add the attribute to avoid this warning and ensure any incorrect format strings are detected here. Fixes: 744c2fe950e9 ("hwmon: (occ) Rework attribute registration for stack usage") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20260203163440.2674340-1-arnd@kernel.org Signed-off-by: Guenter Roeck --- drivers/hwmon/occ/common.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c index b3694a4209b9..89928d38831b 100644 --- a/drivers/hwmon/occ/common.c +++ b/drivers/hwmon/occ/common.c @@ -749,6 +749,7 @@ static ssize_t occ_show_extended(struct device *dev, * are dynamically allocated, we cannot use the existing kernel macros which * stringify the name argument. */ +__printf(7, 8) static void occ_init_attribute(struct occ_attribute *attr, int mode, ssize_t (*show)(struct device *dev, struct device_attribute *attr, char *buf), ssize_t (*store)(struct device *dev, struct device_attribute *attr, -- cgit v1.2.3