lkml.org 
[lkml]   [2020]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCHv1 00/19] Improve SBS battery support
From
Date
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

\
 
 \ /
  Last update: 2020-06-01 12:42    [W:0.197 / U:8.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site