[PATCH AUTOSEL 4.14 5/9] ARM: dts: rockchip: disable arm_global_timer on rk3066 and rk3188

[Sasha Levin]

From: Johan Jonker <jbx6244@xxxxxxxxx>

[ Upstream commit da74858a475782a3f16470907814c8cc5950ad68 ]

The clock source and the sched_clock provided by the arm_global_timer
on Rockchip rk3066a/rk3188 are quite unstable because their rates
depend on the CPU frequency.

Recent changes to the arm_global_timer driver makes it impossible to use.

On the other side, the arm_global_timer has a higher rating than the
ROCKCHIP_TIMER, it will be selected by default by the time framework
while we want to use the stable Rockchip clock source.

Keep the arm_global_timer disabled in order to have the
DW_APB_TIMER (rk3066a) or ROCKCHIP_TIMER (rk3188) selected by default.

Signed-off-by: Johan Jonker <jbx6244@xxxxxxxxx>
Link: https://lore.kernel.org/r/f275ca8d-fd0a-26e5-b978-b7f3df815e0a@xxxxxxxxx
Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/arm/boot/dts/rk3188.dtsi | 1 -
 arch/arm/boot/dts/rk3xxx.dtsi | 7 +++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/rk3188.dtsi b/arch/arm/boot/dts/rk3188.dtsi
index 74eb1dfa2f6c..3689a23a1bca 100644
--- a/arch/arm/boot/dts/rk3188.dtsi
+++ b/arch/arm/boot/dts/rk3188.dtsi
@@ -546,7 +546,6 @@ &emac {
 
 &global_timer {
 	interrupts = <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_EDGE_RISING)>;
-	status = "disabled";
 };
 
 &local_timer {
diff --git a/arch/arm/boot/dts/rk3xxx.dtsi b/arch/arm/boot/dts/rk3xxx.dtsi
index 4aa6f60d6a22..5f9950704f13 100644
--- a/arch/arm/boot/dts/rk3xxx.dtsi
+++ b/arch/arm/boot/dts/rk3xxx.dtsi
@@ -134,6 +134,13 @@ global_timer: global-timer@1013c200 {
 		reg = <0x1013c200 0x20>;
 		interrupts = <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_EDGE_RISING)>;
 		clocks = <&cru CORE_PERI>;
+		status = "disabled";
+		/* The clock source and the sched_clock provided by the arm_global_timer
+		 * on Rockchip rk3066a/rk3188 are quite unstable because their rates
+		 * depend on the CPU frequency.
+		 * Keep the arm_global_timer disabled in order to have the
+		 * DW_APB_TIMER (rk3066a) or ROCKCHIP_TIMER (rk3188) selected by default.
+		 */
 	};
 
 	local_timer: local-timer@1013c600 {
-- 
2.35.1