Re: [PATCH 2/2] ARM: dts: rockchip: Configure the GPU thermal zone for mickey

From: Doug Anderson
Date: Mon May 20 2019 - 16:24:14 EST


Hi,

On Mon, May 20, 2019 at 10:01 AM Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote:
>
> mickey crams a lot of hardware into a tiny package, which requires
> more aggressive thermal throttling than for devices with a larger
> footprint. Configure the GPU thermal zone to throttle the GPU
> progressively at temperatures >= 60ÂC. Heat dissipated by the
> CPUs also affects the GPU temperature, hence we cap the CPU
> frequency to 1.4 GHz for temperatures above 65ÂC. Further throttling
> of the CPUs may be performed by the CPU thermal zone.
>
> The configuration matches that of the downstram Chrome OS 3.14

s/downstram/downstream


> + cooling-maps {
> + /* After 1st level throttle the GPU down to as low as 400 MHz */
> + gpu_warmish_limit_gpu {
> + trip = <&gpu_alert_warmish>;
> + cooling-device = <&gpu THERMAL_NO_LIMIT 1>;

As per my comment in patch #1, you are probably ending up throttling
to 500 MHz, not 400 MHz. Below will all have similar problems unless
we actually delete the 500 MHz operating point.


> + };
> +
> + /*
> + * Slightly after we throttle the GPU, we'll also make sure that
> + * the CPU can't go faster than 1.4 GHz. Note that we won't
> + * throttle the CPU lower than 1.4 GHz due to GPU heat--we'll
> + * let the CPU do the rest itself.
> + */
> + gpu_warm_limit_cpu {
> + trip = <&gpu_alert_warm>;
> + cooling-device = <&cpu0 4 4>;

Shouldn't you list cpu1, cpu2, and cpu3 too? That'd match what
upstream did elsewhere in this file?