[PATCH 6.0 020/157] ARM: dts: rockchip: disable arm_global_timer on rk3066 and rk3188

Greg Kroah-Hartman
2022-12-12T13:35:46Z

From: Johan Jonker <jbx6244@gmail.com>

[ 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@gmail.com>
Link: https://lore.kernel.org/r/f275ca8d-fd0a-26e5-b978-b7f3df815e0a@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 b8f34bef0efa..44b54af0bbf9 100644
--- a/arch/arm/boot/dts/rk3188.dtsi
+++ b/arch/arm/boot/dts/rk3188.dtsi
@@ -607,7 +607,6 @@

&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 616a828e0c6e..17e89d30de78 100644
--- a/arch/arm/boot/dts/rk3xxx.dtsi
+++ b/arch/arm/boot/dts/rk3xxx.dtsi
@@ -76,6 +76,13 @@
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