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@xxxxxxxxxx/ 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@xxxxxxxxxx> --- drivers/power/supply/power_supply_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 8f6025acd10a..b38bff4dbfc7 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -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; --- base-commit: 82e4255305c554b0bb18b7ccf2db86041b4c8b6e change-id: 20240704-topic-sm8x50-upstream-fix-battmgr-temp-tz-warn-077166861efb Best regards, -- Neil Armstrong <neil.armstrong@xxxxxxxxxx>
