From 513c43328b189874fdfee3ae99cac81e5502e7f7 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Wed, 5 Oct 2022 11:34:03 +0200 Subject: [PATCH] arm64: dts: mediatek: mt8195: Fix CPUs capacity-dmips-mhz The capacity-dmips-mhz parameter was miscalculated: this SoC runs the first (Cortex-A55) cluster at a maximum of 2000MHz and the second (Cortex-A78) cluster at a maximum of 3000MHz. In order to calculate the right capacity-dmips-mhz, the following test was performed: 1. CPUFREQ governor was set to 'performance' on both clusters 2. Ran dhrystone with 500000000 iterations for 10 times on each cluster 3. Calculate the mean result for each cluster 4. Calculate DMIPS/MHz: dmips_mhz = dmips_per_second / cpu_mhz 5. Scale results to 1024: result_c0 = (dmips_mhz_c0 - min_dmips_mhz(c0, c1)) / (max_dmips_mhz(c0, c1) - min_dmips_mhz(c0, c1)) * 1024 The mean results for this SoC are: Cluster 0 (LITTLE): 11990400 Dhry/s Cluster 1 (BIG): 59809036 Dhry/s The calculated scaled results are: Cluster 0: 307,934312801831 (rounded to 308) Cluster 1: 1024 Fixes: 37f2582883be ("arm64: dts: Add mediatek SoC mt8195 and evaluation board") Signed-off-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20221005093404.33102-1-angelogioacchino.delregno@collabora.com Signed-off-by: Matthias Brugger --- arch/arm64/boot/dts/mediatek/mt8195.dtsi | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/boot/dts/mediatek/mt8195.dtsi b/arch/arm64/boot/dts/mediatek/mt8195.dtsi index 6c90ff4b3746..e078703674ed 100644 --- a/arch/arm64/boot/dts/mediatek/mt8195.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt8195.dtsi @@ -37,7 +37,7 @@ enable-method = "psci"; performance-domains = <&performance 0>; clock-frequency = <1701000000>; - capacity-dmips-mhz = <578>; + capacity-dmips-mhz = <308>; cpu-idle-states = <&cpu_off_l &cluster_off_l>; next-level-cache = <&l2_0>; #cooling-cells = <2>; @@ -50,7 +50,7 @@ enable-method = "psci"; performance-domains = <&performance 0>; clock-frequency = <1701000000>; - capacity-dmips-mhz = <578>; + capacity-dmips-mhz = <308>; cpu-idle-states = <&cpu_off_l &cluster_off_l>; next-level-cache = <&l2_0>; #cooling-cells = <2>; @@ -63,7 +63,7 @@ enable-method = "psci"; performance-domains = <&performance 0>; clock-frequency = <1701000000>; - capacity-dmips-mhz = <578>; + capacity-dmips-mhz = <308>; cpu-idle-states = <&cpu_off_l &cluster_off_l>; next-level-cache = <&l2_0>; #cooling-cells = <2>; @@ -76,7 +76,7 @@ enable-method = "psci"; performance-domains = <&performance 0>; clock-frequency = <1701000000>; - capacity-dmips-mhz = <578>; + capacity-dmips-mhz = <308>; cpu-idle-states = <&cpu_off_l &cluster_off_l>; next-level-cache = <&l2_0>; #cooling-cells = <2>; -- 2.20.1