The driver exports type. It reads "BMS" (Battery Management System). But upower doesn't know that type (it isn't in vanilla kernel) and while detecting the power supply type[1], it defaults to battery for any unknown power supply device type[2].
[1]: http://cgit.freedesktop.org/upower/tree/src/linux/up-device-supply.c#n955 [2]: http://cgit.freedesktop.org/upower/tree/src/linux/up-device-supply.c#n1019 2014-06-05 0:42 GMT+02:00 Bastien Nocera <had...@hadess.net>: > On Wed, 2014-06-04 at 22:34 +0200, Vojtech Bocek wrote: >> Hello, >> on Google Nexus 5, there is a Linux kernel driver used to change >> charging current according to battery's temperature (too hot -> lower >> the current)[1]. This driver exports as type "BMS" (battery management >> system, not present in vanilla kernel) in sysfs, and because upower >> considers any unknown device which doesn't have an "online" file in >> sysfs a battery, it thinks the device has two batteries. This causes >> the GUI to report wrong battery percentage, because it adds values >> from both "batteries" (one of which is always 0) and divides them by >> two. >> >> The point is I don't think defaulting to battery is a good idea. But I >> don't know if it is okay not to - will it break stuff like UPS if >> upower won't default to battery? What if we check for presence of >> "capacity" file in sysfs (which that temperature driver doesn't have), >> is that okay? >> >> Basically, I'd like to get this properly fixed, but I don't know >> enough about power supply devices to post a patch, so I'd be glad for >> any input on this issue. > > Simply fix the driver to export a "type". That's the way you'd fix it > for any of the in-kernel drivers. > _______________________________________________ devkit-devel mailing list devkit-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/devkit-devel
