Comment 37 for bug 194719

After briefly discussing this bug with Seb and Brian yesterday, it is worth noting that we should consider one of these options, too:

1) Drop this patch (01_proc_sys_batteries);
2) Invert the logic in this patch so that Gutsy's behaviour (reading /proc/acpi) is restored. This means ignoring sysfs for power in instances where both /proc/acpi and sysfs exist.

From what I gather, the sysfs interface is preferable to /proc/acpi, but Seb mentioned there also being backlight issues even with the slew of patches backported from fd.o hal.git.

Choosing option (1) above is fairly straightforward: it eliminates this and several other bugs at the expense of possibly duplicated power source entries in g-p-m (this latter bit possibly being as major as "omgconfusedbbq" - a minor annoyance but bearable IMO). Gutsy's behaviour will be restored mostly (save the duplication).

Choosing option (2) above is less straightforward: it also eliminates this and several other bugs; Gutsy's behaviour will be restored. However, Ubuntu will need to maintain this "inverted patch" for several years, since upstream has already deprecated reading /proc/acpi for power in favour of sysfs. Ultimately the questions involved must include, "Will the power estimation and backlight regressions be fixed in time for Hardy?"

In light of 8.04 being LTS, we should entertain keeping the path that seems to cause fewer regressions.

Thoughts?