This adds CONFIG_FAN_UPDATE_PERIOD to limit the frequency at which
the fan speeds are updated. Short version: the CPU core temp
fluctuates rapidly, causing the fans turn off and on annoyingly
often (assuming you have good hearing and are in a quiet room).
With this CL, we limit the speed changes to only once every N
seconds. N should be long enough to be less annoying, yet short
enough that the CPU doesn't overheat while we're not looking.
BUG=chrome-os-partner:34789
BRANCH=ToT,samus
TEST=manual
Let it sit quietly, then visit a busy webpage, then let it sit a
while. The fan speed should only change every 10 seconds or so,
not every second.
Change-Id: Id985350394f24d56dc4a1e51af09487ac643285b
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/250501
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
d64bb99149