Files
OpenCellular/chip
Vic Yang c288fcf281 mec1322: Keep CPU at high clock frequency to speed up hibernate
When going into and waking from hibernation, we should keep CPU at high
clock frequency so that we can save and restore chip state faster. This
is especially true for the wake-up case as it affects AP boot time.

This CL keeps the CPU at 12MHz for saving state and clocks it up to
48MHz for restoring.

With this, the wake-up time (time from GPIO interrupt to completely
restoring chip state) reduces from 11ms to 0.85ms.

BUG=None
TEST=Measure wake-up time with logic analyzer
BRANCH=None

Change-Id: Ib470a3d38959247b082cc7a5fd2d889cdc2a15ca
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/206308
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
2014-07-03 02:52:30 +00:00
..