diff options
| author | Bill Richardson <wfrichar@chromium.org> | 2014-11-05 12:43:57 -0800 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-11-06 02:28:22 +0000 |
| commit | 41cde665166da1aced2ece17f7b503c78cdb5c8f (patch) | |
| tree | 6e95a130dadbd38846ad8cf32124ccdbb49ff353 /include/fan.h | |
| parent | f0809a23997d66265e625d23ebef8dba1465732f (diff) | |
| download | chrome-ec-41cde665166da1aced2ece17f7b503c78cdb5c8f.tar.gz | |
Samus: Handle fan startup in the EC, not the fan controller
The fans on samus have a recommended minimum duty cycle of 20%
while running, but 30% in order to start. We've been using the
EC's built-in fan controller for the start requirement, but it
has a minimum fast-start duty cycle of 50%. It turns out that
that speed is noticeably noisy.
This change handles the startup with logic in the EC instead, so
that the fan only tries to spin at 30% initially (or if it drops
too much below the minimum turning speed).
BUG=chrome-os-partner:33429
BRANCH=ToT,samus
TEST=make buildall -j
Boot the system, let it idle with the browser windows closed, the
browse a bit, then idle. Listen for changes to the fans.
Before, I could hear the fans kick in and out as the AP load
changed. Now it's much quieter.
Change-Id: Id35215520c064eb6843686ec8bb5f3618dac6cf6
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/227658
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Diffstat (limited to 'include/fan.h')
| -rw-r--r-- | include/fan.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/fan.h b/include/fan.h index a8352987d8..bd94ba8bd1 100644 --- a/include/fan.h +++ b/include/fan.h @@ -11,7 +11,9 @@ /* Characteristic of each physical fan */ struct fan_t { unsigned int flags; + /* rpm_min is to keep turning. rpm_start is to begin turning */ int rpm_min; + int rpm_start; int rpm_max; /* Hardware channel number (the meaning is chip-specific) */ int ch; |