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* [PATCH] ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend
@ 2019-05-21 23:49 Douglas Anderson
  2019-05-22  8:04 ` Heiko Stuebner
  0 siblings, 1 reply; 2+ messages in thread
From: Douglas Anderson @ 2019-05-21 23:49 UTC (permalink / raw)
  To: Heiko Stuebner
  Cc: Mark Rutland, devicetree, briannorris, linux-kernel, Rob Herring,
	Douglas Anderson, linux-rockchip, mka, ryandcase,

This is similar to commit e6186820a745 ("arm64: dts: rockchip: Arch
counter doesn't tick in system suspend").  Specifically on the rk3288
it can be seen that the timer stops ticking in suspend if we end up
running through the "osc_disable" path in rk3288_slp_mode_set().  In
that path the 24 MHz clock will turn off and the timer stops.

To test this, I ran this on a Chrome OS filesystem:
  before=$(date); \
  suspend_stress_test -c1 --suspend_min=30 --suspend_max=31; \
  echo ${before}; date

...and I found that unless I plug in a device that requests USB wakeup
to be active that the two calls to "date" would show that fewer than
30 seconds passed.

NOTE: deep suspend (where the 24 MHz clock gets disabled) isn't
supported yet on upstream Linux so this was tested on a downstream

Signed-off-by: Douglas Anderson <>

 arch/arm/boot/dts/rk3288.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 171231a0cd9b..1e5260b556b7 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -231,6 +231,7 @@
 		clock-frequency = <24000000>;
+		arm,no-tick-in-suspend;
 	timer: timer@ff810000 {

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2019-05-21 23:49 [PATCH] ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend Douglas Anderson
2019-05-22  8:04 ` Heiko Stuebner

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