From: Mateusz Majewski <m.majewski2@samsung.com>
Date: Mon, 11 Sep 2023 13:34:14 +0000 (+0200)
Subject: ARM: dts: samsung: exynos4210: enable polling
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ef399736c3ba77fb82d778b1b7285baa65a7e079;p=linux.git

ARM: dts: samsung: exynos4210: enable polling

It seems that thermal in Exynos 4210 is broken without this, as it will
never decrease cooling after increasing it.

Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
Link: https://lore.kernel.org/r/20230911133417.14042-1-m.majewski2@samsung.com
[krzk: fix comment coding style and line wrapping]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---

diff --git a/arch/arm/boot/dts/samsung/exynos4210.dtsi b/arch/arm/boot/dts/samsung/exynos4210.dtsi
index 0e27c3375e2e9..510e8665d1a25 100644
--- a/arch/arm/boot/dts/samsung/exynos4210.dtsi
+++ b/arch/arm/boot/dts/samsung/exynos4210.dtsi
@@ -391,8 +391,16 @@
 };
 
 &cpu_thermal {
-	polling-delay-passive = <0>;
-	polling-delay = <0>;
+	/*
+	 * Exynos 4210 supports thermal interrupts, but only for the rising
+	 * threshold.  This means that polling is not needed for preventing
+	 * overheating, but only for decreasing cooling when possible. Hence we
+	 * poll with a high delay.  Ideally, we would disable polling for the
+	 * first trip point, but this isn't really possible without outrageous
+	 * hacks.
+	 */
+	polling-delay-passive = <5000>;
+	polling-delay = <5000>;
 };
 
 &gic {