@@ -1287,8 +1287,13 @@ static int power_supply_read_temp(struct thermal_zone_device *tzd,
WARN_ON(tzd == NULL);
psy = thermal_zone_device_priv(tzd);
ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
+ /*
+ * The thermal core expects -EAGAIN as non-fatal error,
+ * convert -ENODEV as -EAGAIN since -ENODEV is returned
+ * when a power supply device isn't initialized
+ */
if (ret)
- return ret;
+ return ret == -ENODEV ? -EAGAIN : ret;
/* Convert tenths of degree Celsius to milli degree Celsius. */
*temp = val.intval * 100;
If the thermal core tries to update the temperature from an uninitialized power supply, it will swawn the following warning: thermal thermal_zoneXX: failed to read out thermal zone (-19) But reading from an uninitialized power supply should not be considered as a fatal error, but the thermal core expects the -EAGAIN error to be returned in this particular case. So convert -ENODEV as -EAGAIN to express the fact that reading temperature from an uninitialized power supply shouldn't be a fatal error, but should indicate to the thermal zone it should retry later. It notably removes such messages on Qualcomm platforms using the qcom_battmgr driver spawning warnings until the aDSP firmware gets up and the battery manager reports valid data. Link: https://lore.kernel.org/all/2ed4c630-204a-4f80-a37f-f2ca838eb455@linaro.org/ Fixes: 5bc28b93a36e ("power_supply: power_supply_read_temp only if use_cnt > 0") Fixes: 3be330bf8860 ("power_supply: Register battery as a thermal zone") Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org> --- drivers/power/supply/power_supply_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- base-commit: 82e4255305c554b0bb18b7ccf2db86041b4c8b6e change-id: 20240704-topic-sm8x50-upstream-fix-battmgr-temp-tz-warn-077166861efb Best regards,