Re: [PATCH v2 0/5] arm64: sunxi: Enable the sun4i timer
From: Samuel Holland <samuel@sholland.org>
Date: 2021-03-24 03:52:15
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On 3/22/21 9:18 AM, Daniel Lezcano wrote:
On 22/03/2021 05:47, Samuel Holland wrote:quoted
In preparation for adding CPU idle states, hook up the sun4i timer. Having a non-c3stop clockevent source available is necessary for all CPUs to simultaneously enter a local-timer-stop idle state.Why simultaneously ?
Because the CPU providing (the hrtimer providing) the broadcast timer cannot enter an idle state which would stop that timer. So in my case, with 4 CPUs, I was seeing at most 3 CPUs enter idle at any given time. This prevented any cluster-level idle states from doing anything. After applying this series, I was able to observe the whole cluster powering down when appropriate. Regards, Samuel
quoted
Changes from v1: - Removed H616 changes (depends on an unmerged patch set) - Reworded the patch 4-5 commit messages for clarity - Added Acked-by tags Samuel Holland (5): dt-bindings: timer: Simplify conditional expressions dt-bindings: timer: Add compatibles for sun50i timers arm64: dts: allwinner: a64: Sort watchdog node arm64: dts: allwinner: Add sun4i MMIO timer nodes arm64: sunxi: Build the sun4i timer driver .../timer/allwinner,sun4i-a10-timer.yaml | 42 +++++++++---------- arch/arm64/Kconfig.platforms | 1 + arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 25 +++++++---- arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 9 ++++ 4 files changed, 46 insertions(+), 31 deletions(-)
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