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authorBill Richardson <wfrichar@chromium.org>2014-11-05 12:43:57 -0800
committerchrome-internal-fetch <chrome-internal-fetch@google.com>2014-11-06 02:28:22 +0000
commit41cde665166da1aced2ece17f7b503c78cdb5c8f (patch)
tree6e95a130dadbd38846ad8cf32124ccdbb49ff353 /board/host
parentf0809a23997d66265e625d23ebef8dba1465732f (diff)
downloadchrome-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 'board/host')
-rw-r--r--board/host/fan.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/board/host/fan.c b/board/host/fan.c
index 18127b9eb0..ee7b15ef12 100644
--- a/board/host/fan.c
+++ b/board/host/fan.c
@@ -11,6 +11,7 @@
const struct fan_t fans[] = {
{.flags = FAN_USE_RPM_MODE,
.rpm_min = 1000,
+ .rpm_start = 1500,
.rpm_max = 5000,
.ch = 0,
.pgood_gpio = -1,
@@ -49,7 +50,7 @@ int fan_get_rpm_mode(int ch)
return mock_rpm_mode;
}
-static int mock_rpm;
+int mock_rpm;
void fan_set_rpm_target(int ch, int rpm)
{
mock_rpm = rpm;