google/panther: acpi: Fix unstable fan behavior on boot + resume

FLVL is used to keep track of which thermal zones are active, but it is
not initialized upon boot / resume. An initial value of zero corresponds
to all zones being active, which causes the fan to spin at max speed
until the OS changes zones. Fix this annoyance by initializing FLVL to
the lowest temperature zone.

Also, fix a related bug where FLVL may jump to an undesired value. For
example, if FLVL=3 (zones 3 + 4 active), and zone 0 is set to off (it's
already off!), FLVL would previously become 1 (zones 1 + 2 + 3 + 4
active!). Fix this by not taking zone ON / OFF actions if our zone is
already ON / OFF.

BUG=chrome-os-partner:25766, chrome-os-partner:24775
TEST=Suspend / resume on Panther 20 times, verify that thermal zone after
resume matches expectation based upon temperature. Also, stress system
and verify thermal zones become active according to temperature
increase.

Change-Id: Ic60686aa5a67bf40c17497832b086ba09d56111a
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/186455
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Commit-Queue: Shawn Nematbakhsh <shawnn@chromium.org>
Tested-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/186669
Commit-Queue: Stefan Reinauer <reinauer@chromium.org>
Tested-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-on: http://review.coreboot.org/6006
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

0 files changed, 0 insertions, 0 deletions