On Wed, 2016-06-29 at 19:28 +1000, Peter Hutterer wrote: > If the 0x1000 Unified Battery Level Status feature exists, expose the battery > level. > > The main drawback is that while a device is plugged in its battery level is 0. > To avoid exposing that as 0% charge we make up a number based on the charging > status. The reason why you don't get a proper state for the K750 is because it doesn't export a battery status of its own. The UPower code uses a heuristic based on the status of the solar panel: if (priv->lux > 200) { priv->batt_status = HIDPP_DEVICE_BATT_STATUS_CHARGING; } else { priv->batt_status = HIDPP_DEVICE_BATT_STATUS_DISCHARGING; } This is the code in UPower: https://cgit.freedesktop.org/upower/tree/src/linux/hidpp-device.c#n914 The heuristics seem to be fairly consistent with the light level button on the keyboard, which shows green or red depending on whether the device is charging or discharging. This hunk of code is also the reason why the battery percentage doesn't match: kernel hidpp code: Device: /org/freedesktop/UPower/devices/keyboard_hidpp_battery_4 native-path: hidpp_battery_4 percentage: 1% UPower's hidpp code: Device: /org/freedesktop/UPower/devices/keyboard_0003o046Do4002x000F native-path: /sys/devices/pci0000:00/0000:00:14.0/usb3/3- 10/3-10:1.2/0003:046D:C52B.000E/0003:046D:4002.000F percentage: 95% Cheers -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html