[v6,5/5] ARM: dts: rockchip: disable arm-global-timer for rk3188
diff mbox

Message ID 1485866596-32254-6-git-send-email-al.kochet@gmail.com
State New
Headers show

Commit Message

Alexander Kochetkov Jan. 31, 2017, 12:43 p.m. UTC
The clocksource and the sched_clock provided by the arm_global_timer
are quite unstable because their rates depend on the cpu frequency.

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 clocksource.

Let's disable the arm_global_timer in order to have the rockchip
clocksource selected by default.

Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
---
 arch/arm/boot/dts/rk3188.dtsi |    1 +
 1 file changed, 1 insertion(+)

Comments

Heiko Stübner Feb. 1, 2017, 9:48 a.m. UTC | #1
Am Dienstag, 31. Januar 2017, 15:43:16 CET schrieb Alexander Kochetkov:
> The clocksource and the sched_clock provided by the arm_global_timer
> are quite unstable because their rates depend on the cpu frequency.
> 
> 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 clocksource.
> 
> Let's disable the arm_global_timer in order to have the rockchip
> clocksource selected by default.
> 
> Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>

depending on who is picking that up, they can add my
Reviewed-by: Heiko Stuebner <heiko@sntech.de>

if needed.

Later on we might need to look at the rk3066 as well, as it might have the 
same issue.

Patch
diff mbox

diff --git a/arch/arm/boot/dts/rk3188.dtsi b/arch/arm/boot/dts/rk3188.dtsi
index 0dc52fe..44da3d42 100644
--- a/arch/arm/boot/dts/rk3188.dtsi
+++ b/arch/arm/boot/dts/rk3188.dtsi
@@ -546,6 +546,7 @@ 
 
 &global_timer {
 	interrupts = <GIC_PPI 11 0xf04>;
+	status = "disabled";
 };
 
 &local_timer {