kernel/linux.git/drivers/hwmon, branch v6.12.103

hwmon: (pmbus/core) notify on the hwmon device, not the i2c client

2026-08-09T18:23:16+00:00

commit a64a7e8a0b012ba81b0eadbd7afc84ab0dbfd70c upstream. pmbus_notify() calls sysfs_notify() and kobject_uevent() on the i2c client's kobject, but the alarm attributes live on the hwmon class device registered by pmbus_do_probe(). Notifying the parent i2c device is a no-op for both poll(POLLPRI) waiters and udev listeners: the named attribute does not exist on that kobject. Notify the hwmon device instead, so poll() wakes up and "change" uevents fire on the inX_alarm/tempX_alarm attributes when SMBALERT# reports a fault. Fixes: f469bde9afd1 ("hwmon: (pmbus/core) Notify hwmon events") Cc: stable@vger.kernel.org # v6.4+ Signed-off-by: Vincent Jardin Link: https://lore.kernel.org/r/20260723-fix_hwmon_notify_v1-v1-1-5a24c528686d@free.fr Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

hwmon: (npcm750-pwm-fan): stop fan timer on device detach

2026-08-09T18:23:16+00:00

commit f27f6976ea269219c1259a7c2f8c6dfe782540a3 upstream. When a fan tach channel is present, npcm7xx_pwm_fan_probe() starts fan_timer. The timer callback polls tach state and rearms the timer, but the driver has no remove callback or devm cleanup action to stop it. On device detach, the devm-managed driver data and I/O mappings can be released while the timer is still pending or running. Register a devm cleanup action before starting the timer and shut the timer down synchronously from that action. This issue was found by a static analysis tool. Fixes: f1fd4a4db777 ("hwmon: Add NPCM7xx PWM and Fan driver") Cc: stable@vger.kernel.org Signed-off-by: Hongyan Xu Link: https://lore.kernel.org/r/20260729100116.790-1-getshell@seu.edu.cn Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

hwmon: (pmbus) Fix return value from pmbus_update_byte_data()

2026-08-09T18:23:07+00:00

[ Upstream commit a19038a200f18d9e74ac30081797917d0886e16b ] pmbus_update_byte_data() is supposed to return a negative error code or 0. However, if no change is made to the register, it actually returns the register value. This can result in problems if the calling code explicitly expects to see an error code or 0. Fix it to return 0 on success or the error code as expected. Fixes: 11c119986f270 ("hwmon: (pmbus) add helpers for byte write and read modify write") Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix PWM auto temp state array and bounds check

2026-08-09T18:23:06+00:00

[ Upstream commit 92413f439d1ec5e55b73ede8d66a7b971cbd1ced ] In pwm_auto_temp_store(), the parsed user input was missing bounds checks, allowing values > 0xF to overflow into the adjacent channel's bits. Furthermore, the value was being incorrectly written to the pwm_automatic state array instead of pwm_auto_temp. Fix this by rejecting values > 0xF with -EINVAL, and assigning the value to the correct array only after a successful I2C write. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260727034932.0B7C41F000E9@smtp.kernel.org/#t Fixes: 6f9703d0be16 ("hwmon: add support for adt7470") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-8-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix divide-by-zero TOCTOU crash in fan speed read

2026-08-09T18:23:06+00:00

[ Upstream commit 1b46fe9dc8f8de59310f37e6c5e5c0e05ded46c3 ] If the fan data becomes 0 between the FAN_DATA_VALID() check and the FAN_PERIOD_TO_RPM() conversion, it will result in a divide-by-zero crash due to a race with a concurrent update of the cached fan value. Fix a TOCTOU issue by reading fan data once. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260727034929.E29B71F000E9@smtp.kernel.org/ Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-7-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Use cached PWM frequency value

2026-08-09T18:23:06+00:00

[ Upstream commit 60677cd4c28f44d5b307d3029dccece38fcce90f ] adt7470_pwm_read() currently ignores failures returned by pwm1_freq_get(). If the register read fails, the negative error code is returned through *val while the function itself reports success, potentially exposing a negative PWM frequency through sysfs. Fix this by using the cached PWM frequency maintained by the driver, eliminating the register access from the read path. Apart from the corrected error propagation and using the cached value, no functional change is intended. Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-6-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix swapped PWM3 and PWM4 auto mode masks

2026-08-09T18:23:06+00:00

[ Upstream commit a3850231521b06bbbb18c8ebea100320c14a08be ] The ADT7470_PWM3_AUTO_MASK and ADT7470_PWM4_AUTO_MASK macros are currently defined with swapped bit values. According to Table 22 of the ADT7470 datasheet, the Fan Control Mode Configuration for register 0x69 follows the exact same bit position layout as register 0x68: - 0x68 Bit[7] corresponds to BHVR1 (PWM1) -> 0x80 - 0x68 Bit[6] corresponds to BHVR2 (PWM2) -> 0x40 - 0x69 Bit[7] corresponds to BHVR3 (PWM3) -> 0x80 - 0x69 Bit[6] corresponds to BHVR4 (PWM4) -> 0x40 Consequently, PWM3 should use mask 0x80 and PWM4 should use 0x40. This typo did not cause any functional bugs because these specific macros are never referenced in the driver code. Instead, the driver correctly applies the configuration by relying on the modulo parity of the channel index (e.g., `channel % 2`) to selectively apply either ADT7470_PWM1_AUTO_MASK (0x80) or ADT7470_PWM2_AUTO_MASK (0x40). Since the bit layout is identical between the two configuration registers, the hardware is currently configured correctly. Fix the macro definitions to reflect the datasheet accurately and prevent future bugs or confusion during code review and refactoring. As this is a purely cosmetic fix with no functional impact, a backport to stable kernels is not necessary. Fixes: 6f9703d0be16 ("hwmon: add support for adt7470") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-4-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix temperature alarm logic in hwmon_temp_read()

2026-08-09T18:23:06+00:00

[ Upstream commit 1a18c79c4bc44cc5349c60e16b0b744dc6ec5f77 ] During the conversion the alarm callback started interpreting the channel index as an alarm bitmask, resulting in incorrect alarm reporting. Compute the proper alarm bit instead. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260717211224.B9E291F000E9@smtp.kernel.org Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-5-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix busy-loop and I2C flooding in update thread

2026-08-09T18:23:06+00:00

[ Upstream commit cb0b7f9c43b0abbd422a7e4c2c85e91db429207c ] When userspace configures 'auto_update_interval' to 0 via sysfs, the background kthread executes schedule_timeout_interruptible(0), which returns immediately. If 'num_temp_sensors' is concurrently or previously set to 0, the msleep_interruptible() delay inside adt7470_read_temperatures() also becomes 0. This combination forces the background thread into a tight, unbounded busy-loop, hogging the CPU and flooding the I2C bus with a continuous stream of transactions. Fix this vulnerability by raising the lower limit of the clamp_val in auto_update_interval_store() from 0 to 500 milliseconds. This guarantees a reasonable minimum sleep window between sensor updates, protecting the system from intentional or accidental I2C bus denial of service. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260716213252.EACA71F000E9@smtp.kernel.org Fixes: 89fac11cb3e7 ("adt7470: make automatic fan control really work") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-3-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (adt7470) Fix cache updated before hardware write on I2C error

2026-08-09T18:23:06+00:00

[ Upstream commit 05270bd38d9bf88a2f4c212246a8fa29f4032078 ] adt7470_temp_write() and adt7470_pwm_write() update the driver's cached values (temp_min, temp_max, pwm_input, pwm_enable) before issuing the corresponding regmap_write(), and never check whether the write succeeded before committing that update. If the I2C transaction fails, the function correctly propagates the error to the caller, but the cache silently keeps the new value, which was never actually applied to the hardware. Subsequent reads then report a value that does not match the device state. Reorder both write paths to update the cache only after a successful regmap_write(), so the cache always reflects what was actually written to the hardware. Fixes: ef67959c4253 ("hwmon: (adt7470) Convert to use regmap") Signed-off-by: Luiz Angelo Daros de Luca Link: https://lore.kernel.org/r/20260727-adt7470_fixes-v2-2-598e38a46ba6@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin