Hello Daniel,
On 4/4/24 17:16, Daniel Lezcano wrote:
Hi Nico,
a few comments about this description.
On 02/04/2024 05:25, Nicolas Pitre wrote:
From: Nicolas Pitre <npitre@xxxxxxxxxxxx>
Inspired by the vendor kernel but adapted to the upstream thermal
driver version.
[ ... ]
+ thermal_zones: thermal-zones {
+ cpu-little0-thermal {
+ polling-delay = <1000>;
Except if I'm wrong, the driver supports the interrupt mode, so it not necessary to poll
constantly when there is no mitigation. You can remove the line and everywhere else.
+ polling-delay-passive = <250>;
As little CPU, 200ms or 150ms may be more adequate.
+ thermal-sensors = <&lvts_mcu MT8188_MCU_LITTLE_CPU0>;
+
+ trips {
+ cpu_little0_alert: trip-alert {
+ temperature = <85000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
You may want to add a 'hot' trip point in between, so the userspace can be notified and take an
action before reaching 'critical' (like unplugging a CPU)
There's no "notify" function in the driver.
Do you think it's worth adding such 'hot' trip point, though ?
+ cpu_little0_crit: trip-crit {
+ temperature = <100000>;
+ hysteresis = <2000>;
critical is a point of no return. Hysteresis does not make sense.
These comments apply to all thermal zones.
[ .. ]
+ cpu_big0-thermal {
+ polling-delay = <1000>;
+ polling-delay-passive = <250>;
Same comments as the little but may be an even lower value. eg. 100ms.
+ thermal-sensors = <&lvts_mcu MT8188_MCU_BIG_CPU0>;
+
+ trips {
+ cpu_big0_alert: trip-alert {
+ temperature = <85000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
+ cpu_big0_crit: trip-crit {
+ temperature = <100000>;
+ hysteresis = <2000>;
+ type = "critical";
+ };
+ };
+
+ cooling-maps {
+ map0 {
+ trip = <&cpu_big0_alert>;
+ cooling-device = <&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
+ };
[ ... ]
+ gpu1-thermal {
+ polling-delay = <1000>;
+ polling-delay-passive = <250>;
+ thermal-sensors = <&lvts_ap MT8188_AP_GPU1>;
+
+ trips {
+ gpu1_alert: trip-alert {
+ temperature = <85000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
+ gpu1_crit: trip-crit {
+ temperature = <100000>;
+ hysteresis = <2000>;
+ type = "critical";
+ };
+ };
+ };
+
+ gpu2-thermal {
+ polling-delay = <1000>;
+ polling-delay-passive = <250>;
+ thermal-sensors = <&lvts_ap MT8188_AP_GPU2>;
+
+ trips {
+ gpu2_alert: trip-alert {
+ temperature = <85000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
+ gpu2_crit: trip-crit {
+ temperature = <100000>;
+ hysteresis = <2000>;
+ type = "critical";
+ };
+ };
You can add a devfreq cooling device for the GPU here.
I tried but realized then that GPU support has not been added in the DT yet.
So, I added the gpu node (from vendor's kernel), but there are many missing
dependencies. I guess it should be part of another series.
As a result, I can't add such cooling device here.
Julien
