From mboxrd@z Thu Jan  1 00:00:00 1970
From: heiko@sntech.de (Heiko =?ISO-8859-1?Q?St=FCbner?=)
Date: Thu, 03 Dec 2015 02:05:01 +0100
Subject: [RFC] rk3368 idle states
In-Reply-To: <20151202111858.GB18981@red-moon>
References: <20151202111858.GB18981@red-moon>
Message-ID: <2472961.2QZIyIIJQ0@diego>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Lorenzo,

Am Mittwoch, 2. Dezember 2015, 11:18:58 schrieb Lorenzo Pieralisi:
> while reviewing other dts idle states bindings I spotted the following
> snippet in arch/arm64/boot/dts/rockchip/rk3368.dtsi:
> 
> cpu_sleep: cpu-sleep-0 {
>        compatible = "arm,idle-state";
>        arm,psci-suspend-param = <0x1010000>;
>        entry-latency-us = <0x3fffffff>;
>        exit-latency-us = <0x40000000>;
>        min-residency-us = <0xffffffff>;
> };
> 
> Could you please explain to me how you obtained these residency/latency
> values ? They make NO sense whatsoever and I am quite tempted to
> ask you to remove this data from the dts file, it is just wrong.

I took these values verbatim from the vendor kernel when adding the core 
rk3368 support.

I guess I was overly enthusiastic, that psci worked out of the box for smp, 
that I didn't check the latency/residency values enough at that time. As time-
values they are really overly long :-) .


Nevertheless I have inquired now, what the background of those values is.


Heiko