On Sun 2018-11-11 12:57:12, Hans de Goede wrote: > Hi, > > On 11/7/18 5:53 AM, Daniel Drake wrote: > >On Mon, Nov 5, 2018 at 1:19 AM Pavel Machek <pavel@xxxxxx> wrote: > >>Plus, I don't think "100% charge" is right test for "battery full". At > >>least on thinkpads, there's configuration option, and it is common > >>_not_ to charge batterry above 95% or so (to increase its lifetime). > > > >Hans also touched on this area in his response: > > > >>As for this kernel-side fix I do not believe that fixing thus in > >>the kernel is the right thing to do. We try to stay away from > >>heuristics using full_charge_capacity in the kernel since that > >>is not really reliable / deterministic. > > > >I'm not fully convinced by this argument though. > > > >The ACPI spec is not very clear on what conditions you should apply to > >decide when the battery is full. Instead, ACPI seems to provide a > >pretty decent amount of data, and the decision about whether to > >interpret that as "battery full" is left for consumers. > > Right, but in this case the "discharging" status bit is explicitly > set, to me it feels wrong to report "full", when the firmware > is reporting "discharging" IMHO, at best we are "not charging" > (on AC, below the threshold where a new charge cycle starts) and > that is what we are currently reporting. > > Anu heurstics to decide that "not charging" is close enough to full > to report it as full to the user belongs in userspace IMHO. > > Anyways this ultimately is Rafael's call. If Rafael is ok with this > patch then I would like to see Pavel's comment addressed and otherwise > it is fine with me. > > Note that we will still often get the case where a laptop is charged, > reports full, is unplugged for 5 minutes and then replugged and then > reports a capacity of 97% combined with "not charging", so we will > still need to fix userspace to handle this. For the record, I don't think I'm okay with this. There's nothing special about 100% charge. This changes userland ABI and I don't think it has good enough reasons to do that. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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