On Fri, 15 Aug 2025 at 01:35, Marek Vasut
<marek.vasut+renesas@xxxxxxxxxxx> wrote:
> Since the Sparrow Hawk has a smaller PCB than the White Hawk, it tends
> to generate more heat. To prevent potential damage to the board, adjust
> the temperature trip points.
>
> Add four "passive" trip points which increasingly throttle the CPU to
> prevent overheating. The first trip point at 68°C disables the 1.8 GHz
> and 1.7 GHz modes and limits the CPU to 1.5 GHz frequency. The second
> trip point at 72°C disables the 1.5 GHz mode and limits the CPU to 1.0
> GHz frequency. The third trip point at 76°C uses thermal-idle to start
> inserting idle cycles into the CPU instruction stream to cool the CPU
> cores down. The fourth and last trip point at 80°C disables the 1.0 GHz
> mode and limits the CPU to 500 MHz frequency.
>
> In case the SoC heats up further, in case either of the thermal sensors
> readings passes the 100°C, a thermal shutdown is triggered to prevent
> any damage to the hardware.
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> ---
> Cc: Conor Dooley <conor+dt@xxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Cc: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
> Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
> Cc: "Niklas Söderlund" <niklas.soderlund@xxxxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> ---
> V2: Add RB from Niklas
> V3: - Sort DT nodes
> - Update comment on idle states, note the 0..80%
> - Add RB from Geert
Thanks, will queue in renesas-devel for v6.18.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
