Hi Sebastian, On 13.05.2020 20:55, Sebastian Reichel wrote: > This patchset improves support for SBS compliant batteries. Due to > the changes, the battery now exposes 32 power supply properties and > (un)plugging it generates a backtrace containing the following message > without the first patch in this series: > > --------------------------- > WARNING: CPU: 0 PID: 20 at lib/kobject_uevent.c:659 add_uevent_var+0xd4/0x104 > add_uevent_var: too many keys > --------------------------- > > For references this is what an SBS battery status looks like after > the patch series has been applied: > > cat /sys/class/power_supply/sbs-0-000b/uevent > POWER_SUPPLY_NAME=sbs-0-000b > POWER_SUPPLY_TYPE=Battery > POWER_SUPPLY_STATUS=Discharging > POWER_SUPPLY_CAPACITY_LEVEL=Normal > POWER_SUPPLY_HEALTH=Good > POWER_SUPPLY_PRESENT=1 > POWER_SUPPLY_TECHNOLOGY=Li-ion > POWER_SUPPLY_CYCLE_COUNT=12 > POWER_SUPPLY_VOLTAGE_NOW=11441000 > POWER_SUPPLY_CURRENT_NOW=-26000 > POWER_SUPPLY_CURRENT_AVG=-24000 > POWER_SUPPLY_CAPACITY=76 > POWER_SUPPLY_CAPACITY_ERROR_MARGIN=1 > POWER_SUPPLY_TEMP=198 > POWER_SUPPLY_TIME_TO_EMPTY_AVG=438600 > POWER_SUPPLY_TIME_TO_FULL_AVG=3932100 > POWER_SUPPLY_SERIAL_NUMBER=0000 > POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000 > POWER_SUPPLY_VOLTAGE_MAX_DESIGN=10800000 > POWER_SUPPLY_ENERGY_NOW=31090000 > POWER_SUPPLY_ENERGY_FULL=42450000 > POWER_SUPPLY_ENERGY_FULL_DESIGN=41040000 > POWER_SUPPLY_CHARGE_NOW=2924000 > POWER_SUPPLY_CHARGE_FULL=3898000 > POWER_SUPPLY_CHARGE_FULL_DESIGN=3800000 > POWER_SUPPLY_CONSTANT_CHARGE_CURRENT_MAX=3000000 > POWER_SUPPLY_CONSTANT_CHARGE_VOLTAGE_MAX=12300000 > POWER_SUPPLY_MANUFACTURE_YEAR=2017 > POWER_SUPPLY_MANUFACTURE_MONTH=7 > POWER_SUPPLY_MANUFACTURE_DAY=3 > POWER_SUPPLY_MANUFACTURER=UR18650A > POWER_SUPPLY_MODEL_NAME=GEHC This patch landed in linux-next dated 20200529. Sadly it causes a regression on Samsung Exynos-based Chromebooks (Exynos5250 Snow, Exynos5420 Peach-Pi and Exynos5800 Peach-Pit). System boots to userspace, but then, when udev populates /dev, booting hangs: [ 4.435167] VFS: Mounted root (ext4 filesystem) readonly on device 179:51. [ 4.457477] devtmpfs: mounted [ 4.460235] Freeing unused kernel memory: 1024K [ 4.464022] Run /sbin/init as init process INIT: version 2.88 booting [info] Using makefile-style concurrent boot in runlevel S. [ 5.102096] random: crng init done [....] Starting the hotplug events dispatcher: systemd-udevdstarting version 236 [ ok . [....] Synthesizing the initial hotplug events...[ ok done. [....] Waiting for /dev to be fully populated...[ 34.409914] TPS65090_RAILSDCDC1: disabling [ 34.412977] TPS65090_RAILSDCDC2: disabling [ 34.417021] TPS65090_RAILSDCDC3: disabling [ 34.423848] TPS65090_RAILSLDO1: disabling [ 34.429068] TPS65090_RAILSLDO2: disabling Bisect between v5.7-rc1 and next-20200529 pointed me to the first bad commit: [c4b12a2f3f3de670f6be5e96092a2cab0b877f1a] power: supply: sbs-battery: simplify read_read_string_data. However reverting it in linux-next doesn't fix the issue, so the next commits are also relevant to this issue. Let me know how can I help debugging it. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland