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veyron_mickey: Reduce voltage and frequency in recovery mode

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If recovery mode is detected, throttle down APLL frequency to 600MHz
and VDD_ARM to 900mV. This is intended to mitigate the possibility
of thermal shutdown if the system is left at the recovery screen for
a long period of time.

Experimentally, going lower than 600MHz didn't help decrease
temperature significantly and added a few seconds to recovery
boot time.

BUG=chrome-os-partner:41201
BRANCH=firmware-veyron
TEST=built and booted on mickey, normal mode boot time was normal (~1.8s)
and RK808 temperature remained steady at recovery screen for ~14 hours.
Signed-off-by: David Hendricks <dhendrix@chromium.org>

Change-Id: I82cbc1f591cbfae5ccf4e99e468f2b053c835639
Reviewed-on: https://chromium-review.googlesource.com/299718
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
This commit is contained in:
David Hendricks 2015-09-15 19:37:44 -07:00 • committed by ChromeOS bot
commit 9e86c6decb
1 changed files with 8 additions and 0 deletions
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8
src/mainboard/google/veyron_mickey/mainboard.c
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@ -102,6 +102,14 @@ static void mainboard_init(device_t dev)
elog_init();
elog_add_watchdog_reset();
elog_add_boot_reason();
/* If recovery mode is detected, reduce frequency and voltage to reduce
* heat in case machine is left unattended. chrome-os-partner:41201. */
if (recovery_mode_enabled()) {
printk(BIOS_DEBUG, "Reducing APLL freq for recovery mode.\n");
rkclk_configure_cpu(APLL_600_MHZ);
rk808_configure_buck(1, 900);
}
}
static void mainboard_enable(device_t dev)