Bug 93871

Summary:	Battery status reported by /sys is incorrect on HP Elitepad 1000 G2 (Baytrail)
Product:	ACPI	Reporter:	Thomas Gibbs (thomasapgibbs)
Component:	Power-Battery	Assignee:	Aaron Lu (aaron.lu)
Status:	CLOSED INSUFFICIENT_DATA
Severity:	normal	CC:	aaron.lu
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	3.19	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	ACPI dump from ElitePad 1000 G2

Description Thomas Gibbs 2015-02-25 17:53:14 UTC

Created attachment 168231 [details]
ACPI dump from ElitePad 1000 G2

Hi,

I'm attempting to run 3.19 on the HP ElitePad (BayTrail tablet platform). Everything appears to work properly, other than the battery status information reported in /sys. Regardless of whether the tablet is plugged in and charging or unplugged the output is always this:

user@machine:~$ cat /sys/class/power_supply/BAT0/uevent
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=7400000
POWER_SUPPLY_VOLTAGE_NOW=7400000
POWER_SUPPLY_CURRENT_NOW=100000
POWER_SUPPLY_CHARGE_FULL_DESIGN=3375000
POWER_SUPPLY_CHARGE_FULL=3375000
POWER_SUPPLY_CHARGE_NOW=2000000
POWER_SUPPLY_CAPACITY=59
POWER_SUPPLY_MODEL_NAME=PABAS0241231
POWER_SUPPLY_MANUFACTURER=HP
POWER_SUPPLY_SERIAL_NUMBER=41167 

This is the case for both Ubuntu 3.19 kernel, and self-compiled kernels, 3.18 and 3.19. I've tried the patch given in bug #90161 but it doesn't make any difference in this case. Not knowing how ACPI etc works I'm pretty stumped.

The ACPI dump is attached. If somebody can point me in the right direction I'm happy to investigate further.

Comment 1 Aaron Lu 2015-03-31 07:44:40 UTC

Does CONFIG_ACPI_I2C_OPREGION get set? I tested on ASUS T100, which is also a Baytrail-T platform on v4.0-rc6, it doesn't have this problem. But things may be different.

Comment 2 Aaron Lu 2015-06-03 08:06:32 UTC

ping