hwmon: (acpi_power_meter) Fix 4.29 MW bug
[ Upstream commit
1fefca6c57fb928d2131ff365270cbf863d89c88 ]
The ACPI specification says:
"If an error occurs while obtaining the meter reading or if the value
is not available then an Integer with all bits set is returned"
Since the "integer" is 32 bits in case of the ACPI power meter,
userspace will get a power reading of 2^32 * 1000 miliwatts (~4.29 MW)
in case of such an error. This was discovered due to a lm_sensors
bugreport (https://github.com/lm-sensors/lm-sensors/issues/460).
Fix this by returning -ENODATA instead.
Tested-by: <urbinek@gmail.com>
Fixes:
de584afa5e18 ("hwmon driver for ACPI 4.0 power meters")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231124182747.13956-1-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>