Comment 29 for bug 1752437

(In reply to g.fitch from comment #15)
> Hi Lukas,
>
> I tested it with KDE 5 (17.12.3) with one of the drm-next kernels:
> Linux tau-ceti 4.16.0-rc7-gc5902206599d-dirty #4 SMP PREEMPT Sun Apr 15
> 17:37:13 BST 2018 x86_64 AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx
> AuthenticAMD GNU/Linux
>
>
> Your patch works fine for the touchscreen on this laptop - touchscreen is
> detectable and usable with both finger and the supplied pen.
>
> The relevant bit of dmesg is:
>
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: ACPI slave is
> not supported yet
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: Standard-mode
> HCNT:LCNT = 642:749
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: Fast-mode
> HCNT:LCNT = 132:239
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: GPIO lookup for
> consumer scl
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: using ACPI for
> GPIO lookup
> Apr 15 17:47:11 tau-ceti kernel: acpi AMDI0010:00: GPIO: looking up scl-gpios
> Apr 15 17:47:11 tau-ceti kernel: acpi AMDI0010:00: GPIO: looking up scl-gpio
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: using lookup
> tables for GPIO lookup
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: lookup for GPIO
> scl failed
> Apr 15 17:47:11 tau-ceti kernel: i2c-dev: adapter [Synopsys DesignWare I2C
> adapter] registered as minor 5
> Apr 15 17:47:11 tau-ceti kernel: i2c i2c-5: adapter [Synopsys DesignWare I2C
> adapter] registered
> Apr 15 17:47:11 tau-ceti kernel: acpi ELAN0732:00: GPIO: looking up 0 in _CRS
> Apr 15 17:47:11 tau-ceti kernel: gpio gpiochip0: Persistence not supported
> for GPIO 89
> Apr 15 17:47:11 tau-ceti kernel: i2c_hid i2c-ELAN0732:00: probe
> Apr 15 17:47:11 tau-ceti kernel: i2c i2c-5: master_xfer[0] W, addr=0x10,
> len=2
> Apr 15 17:47:11 tau-ceti kernel: i2c i2c-5: master_xfer[1] R, addr=0x10,
> len=30
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: i2c_dw_xfer:
> msgs: 2
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: enabled=0x1
> stat=0x10
> Apr 15 17:47:11 tau-ceti kernel: i2c_designware AMDI0010:00: enabled=0x1
> stat=0x504
> Apr 15 17:47:11 tau-ceti last message repeated 9 times
>
>
>
> The patch creates one issue, which is that the following warning now pops up
> at boot:
>
> The battery in your keyboard ("ELAN0732:00 04F3:2537") is low, and the
> device may turn itself off at any time. Please replace or charge the battery
> as soon as possible.
>
> However all other peripherals and buttons work fine, so it's a minor
> nuisance.
>
> Thank you for getting us this far!

It looks like upower/i2c-hid think the touchscreen has a battery (which is false) and reports a invalid power value of 0. When I get a working desktop I could take a look for it. Meanwhile switching CONFIG_HID_BATTERY_STRENGTH off should silence the warning if you don't rely on this feature.