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From: narmstrong@baylibre.com (Neil Armstrong)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM64: dts: meson-gxbb-odroidc2: Disable SCPI DVFS
Date: Thu,  5 Jan 2017 16:02:29 +0100	[thread overview]
Message-ID: <1483628549-29486-1-git-send-email-narmstrong@baylibre.com> (raw)

The current hardware is not able to run with all cores enabled at a
cluster frequency superior at 1536MHz.
But the currently shipped u-boot for the platform still reports an OPP
table with possible DVFS frequency up to 2GHz, and will not change since
the off-tree linux tree supports limiting the OPPs with a kernel parameter.
A recent u-boot change reports the boot-time DVFS around 100MHz and
the default performance cpufreq governor sets the maximum frequency.
Previous version of u-boot reported to be already at the max OPP and
left the OPP as is.
Nevertheless, other governors like ondemand could setup the max frequency
and make the system crash.

This patch disables the DVFS clock and disables cpufreq.

Fixes: 70db166a2baa ("ARM64: dts: meson-gxbb: Add SCPI with cpufreq & sensors Nodes")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
index 238fbea..5e63e3b 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
@@ -137,6 +137,10 @@
 	};
 };
 
+&scpi_dvfs {
+	status = "disabled";
+};
+
 &uart_AO {
 	status = "okay";
 	pinctrl-0 = <&uart_ao_a_pins>;
-- 
1.9.1

             reply	other threads:[~2017-01-05 15:02 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-05 15:02 Neil Armstrong [this message]
2017-01-05 19:04 ` [PATCH] ARM64: dts: meson-gxbb-odroidc2: Disable SCPI DVFS Michał Zegan
2017-01-06  8:04   ` Neil Armstrong
2017-01-06 11:54   ` Sudeep Holla
2017-01-06 13:12     ` Michał Zegan

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