[Bug 162859] [acpi] ACPI battery/acline monitoring partialy working (switching)

[Ian Smith]

On Wed, 7 Jan 2015 20:23:51 +0200, Juris Kaminskis wrote:
 > 2015-01-05 17:27 GMT+02:00 Juris Kaminskis <juris.kaminskis at gmail.com>:

 > > 2015-01-04 15:17 GMT+02:00 Ian Smith <smithi at nimnet.asn.au>:
 > > >
 > > > On Sat, 3 Jan 2015 11:45:05 +0000, bugzilla-noreply at freebsd.org wrote:
 > > >
 > > > Please excuse this off-'zilla merely speculative response.  No time, but
 > > > I've spent (wasted?) some time chasing a couple of these outside the PR.
 > > >
 > > >  > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=162859
 > > >  >
 > > >  > --- Comment #14 from juris <juris.kaminskis at gmail.com> ---
 > > >  > Problem on /head/ branch is introduced with revision 216942.
 > > >
 > > > If true (in all cases) this is great news for those with a variety of HP
 > > > laptops that have been experiencing partial - or in some cases complete
 > > > after boot - failures in CMBAT monitoring since 9.0.  And a Macbook Pro.
 > > >
 > > > So, reverting rev 216942 fixes it for you?  On what FreeBSD version?
 > >
 > > I have compiled head branch revision 216941 and battery status via
 > > acpiconf works. When compiling from source revision 216942 acpiconf stops
 > > responding. I also tried to remove r216942 and compiled from source release
 > > 9.3, but there battery status was not working. Apparently there are more
 > > things than just one that breaks HP ACPI .

 > Sorry for my previous email that was confusing. I did not revert r216941
 > when compiled release 9.3. So when I did that, battery status works. I also
 > compiled release 10.1 with excluding r216942, and battery status works. So
 > this single change for some reason creates problem for HP laptops.

So it seems; I'll post a proper response based on the text above and my 
musings below to bugzilla .. such details are important, and I should 
have been game to speculate there originally, my apologies to all.

It's important to note that this PR was originally filed on 2011-11-24 
21:50 UTC by msuszko, at version 9.0-PRERELEASE.  revision 216942 was 
committed to head on Jan 4 00:10:29 2011 UTC (4 years ago) by jkim, 
while head was 9-CURRENT, and hasn't changed since.  It seems fortunate, 
for HP laptops anyway, that this was not apparently merged back to 8.x.

cheers, Ian

 > > > If so, with scant comprehension of the code, questions that occur:
 > > >
 > > > a) did that revision fix some existing problem, the reverting of which
 > > > might reestablish problem/s in other machines?  jkim?
 > > >
 > > > b) what is it in various HP ACPI implementations that don't seem to be a
 > > > reported problem on other hardware, particularly concerning EC handling?
 > > >
 > > > c) if this was wrong (for HPs), what would be right?  (the hard one :)
 > > >
 > > > cheers, Ian