Bisected regression from 3.17 still present in 3.19-rc1

["Carlos R. Mafra" <crmafra2@gmail.com>]

The laptop is a 2-year-old macbook Pro with retina display.

I use a dockapp called wmlaptop2 (http://repo.or.cz/w/wmlaptop2.git)
which, among other things, displays battery information (% of charge
remaining etc).

With the kernel v3.17 the battery information stopped working and it
still does not work in the latest v3.19-rc1.

Looking at what wmlaptop2 does I noticed that one entry inside
/sys/class/power_supply is not present in a bad kernel.

In a good kernel:

[mafra@linux-g29b:~]$ ls /sys/class/power_supply/
ADP1@  BAT0@

but in v3.17 onwards there's no BAT0@ entry:

[mafra@linux-g29b:~]$ ls /sys/class/power_supply/
ADP1@

I bisected the problem to this commit:

commit 7bc5a2bad0b8d9d1ac9f7b8b33150e4ddf197334
Author: Matthew Garrett <matthew.garrett@nebula.com>
Date:   Sat Sep 20 13:19:47 2014 +0200

    ACPI: Support _OSI("Darwin") correctly
    

Is there anything else I can do to help fixing this?

PS: the bisect log:

git bisect start
# bad: [f114040e3ea6e07372334ade75d1ee0775c355e1] Linux 3.18-rc1
git bisect bad f114040e3ea6e07372334ade75d1ee0775c355e1
# good: [bfe01a5ba2490f299e1d2d5508cbbbadd897bbe9] Linux 3.17
git bisect good bfe01a5ba2490f299e1d2d5508cbbbadd897bbe9
# good: [35a9ad8af0bb0fa3525e6d0d20e32551d226f38e] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
git bisect good 35a9ad8af0bb0fa3525e6d0d20e32551d226f38e
# bad: [d6dd50e07c5bec00db2005969b1a01f8ca3d25ef] Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad d6dd50e07c5bec00db2005969b1a01f8ca3d25ef
# bad: [bf65dea87e87c53ba4f97c6432761498bc977efd] Merge tag 'edac/v3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac
git bisect bad bf65dea87e87c53ba4f97c6432761498bc977efd
# bad: [b211e9d7c861bdb37b86d6384da9edfb80949ceb] Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
git bisect bad b211e9d7c861bdb37b86d6384da9edfb80949ceb
# good: [80213c03c4151d900cf293ef0fc51f8d88495e14] Merge tag 'pci-v3.18-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
git bisect good 80213c03c4151d900cf293ef0fc51f8d88495e14
# good: [7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0] nosave: consolidate __nosave_{begin,end} in <asm/sections.h>
git bisect good 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0
# bad: [49a09c9ab012017c4673b86dbb28c616cf8f2381] Merge branch 'pm-domains'
git bisect bad 49a09c9ab012017c4673b86dbb28c616cf8f2381
# bad: [88b42a4883a7783972c8fc607e60bd3f027e24de] Merge branch 'pm-genirq'
git bisect bad 88b42a4883a7783972c8fc607e60bd3f027e24de
# bad: [a13f453140d542f9d5a0ee15601531c72e5401d7] Merge branch 'acpi-lpss'
git bisect bad a13f453140d542f9d5a0ee15601531c72e5401d7
# bad: [939558f2a4b7851c11ce8d08387730914a1e1f5f] Merge branch 'acpi-apple'
git bisect bad 939558f2a4b7851c11ce8d08387730914a1e1f5f
# good: [5a0b8deeeb19906b24a48d0078aa6b64dc0b4dab] ACPICA: Clear all non-wakeup GPEs in acpi_hw_enable_wakeup_gpe_block()
git bisect good 5a0b8deeeb19906b24a48d0078aa6b64dc0b4dab
# bad: [7bc5a2bad0b8d9d1ac9f7b8b33150e4ddf197334] ACPI: Support _OSI("Darwin") correctly
git bisect bad 7bc5a2bad0b8d9d1ac9f7b8b33150e4ddf197334
# good: [9faf6136ff4647452580b019f4b16f8c5082e589] ACPI / SBS: Disable smart battery manager on Apple
git bisect good 9faf6136ff4647452580b019f4b16f8c5082e589
# first bad commit: [7bc5a2bad0b8d9d1ac9f7b8b33150e4ddf197334] ACPI: Support _OSI("Darwin") correctly
[mafra@linux-g29b:linux-2.6]$