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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Douglas Anderson <dianders@chromium.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.2 005/131] ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend
Date:   Mon,  5 Aug 2019 15:01:32 +0200
Message-Id: <20190805124951.787798602@linuxfoundation.org>
In-Reply-To: <20190805124951.453337465@linuxfoundation.org>
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[ Upstream commit 8ef1ba39a9fa53d2205e633bc9b21840a275908e ]

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
kernel.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 aa017abf4f421..f7bc886a4b513 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -231,6 +231,7 @@
 			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>,
 			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>;
 		clock-frequency = <24000000>;
+		arm,no-tick-in-suspend;
 	};
 
 	timer: timer@ff810000 {
-- 
2.20.1