I'm not surprised that there exist a number of userspace programs that assume the buggy ACPI battery behavior is the only one, but this does leave us in the previous situation where there's a clear bug in the ACPI driver. > But, the patch was actually doing the right thing, according to: > > Documentation/ABI/testing/sysfs-class-power This is the key issue, since it's entirely plausible for a program assuming non-negative battery current to run on a non-ACPI platform and misbehave in the same way. If we're not going to fix the ACPI driver to behave as specified for the kernel ABI, then the ABI needs to be redefined to reflect the actual behavior. It's either that or we give userspace an opportunity to fix itself (and I'm not sure exactly how that would be done such that the clients which need to be fixed discover that they need to be) and correct the driver's behavior later.
