linux-kernel - Re: [PATCH] arm64: dts: exynos: fix type of thermal trip points for Exynos7

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Date:   Tue, 15 May 2018 14:59:33 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Cc:     Alim Akhtar <alim.akhtar@...sung.com>,
        "linux-samsung-soc@...r.kernel.org" 
        <linux-samsung-soc@...r.kernel.org>, linux-pm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] arm64: dts: exynos: fix type of thermal trip points for Exynos7

On Tue, May 15, 2018 at 2:37 PM, Bartlomiej Zolnierkiewicz
<b.zolnierkie@...sung.com> wrote:
> Currently Exynos thermal driver treats as "active" all specified
> trip points before reaching maximum number of hardware supported
> trip points.

The trip point type describe the way how system should act - use
active or passive cooling. It is independent of thermal driver. I do
not understand what is exactly wrong... maybe except whether the trip
point is active/passive looks like property of board, not SoC itself,
but your patch does not address it.

> Moreover polling-delay-passive is specified as "0"
> in exynos7.dtsi (IOW passive polling is disabled).

Which is perfectly fine. TMU driver for Exynos7 supports up to eight
trip points in interrupt mode so having polling mode = 0 is good. IOW
passive polling is disabled just like active polling is disabled so
what did you want to say here?

Best regards,
Krzysztof

> Therefore fix
> type of cpu-alert-0 to cpu-alert6 trip points to be "active"
> instead of "passive" (cpu-alert-7 type is "critical" so it
> doesn't need a fixup).
>
> Cc: Alim Akhtar <alim.akhtar@...sung.com>
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
> ---
>  arch/arm64/boot/dts/exynos/exynos7-trip-points.dtsi |   14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> Index: b/arch/arm64/boot/dts/exynos/exynos7-trip-points.dtsi
> ===================================================================
> --- a/arch/arm64/boot/dts/exynos/exynos7-trip-points.dtsi       2018-05-15 13:57:55.822172496 +0200
> +++ b/arch/arm64/boot/dts/exynos/exynos7-trip-points.dtsi       2018-05-15 14:23:12.594016481 +0200
> @@ -10,37 +10,37 @@ trips {
>         cpu-alert-0 {
>                 temperature = <75000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-1 {
>                 temperature = <80000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-2 {
>                 temperature = <85000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-3 {
>                 temperature = <90000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-4 {
>                 temperature = <95000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-5 {
>                 temperature = <100000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-alert-6 {
>                 temperature = <110000>; /* millicelsius */
>                 hysteresis = <10000>; /* millicelsius */
> -               type = "passive";
> +               type = "active";
>         };
>         cpu-crit-0 {
>                 temperature = <115000>; /* millicelsius */
>