Re: [PATCH v2 0/5] arm64: sunxi: Enable the sun4i timer

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(-)