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From: mylene.josserand@free-electrons.com (Mylène Josserand)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 5/5] arm: dts: sun8i: a83t: Fix undefined offset with virtual timer
Date: Fri, 29 Dec 2017 11:55:06 +0100	[thread overview]
Message-ID: <20171229105506.24851-6-mylene.josserand@free-electrons.com> (raw)
In-Reply-To: <20171229105506.24851-1-mylene.josserand@free-electrons.com>

The ARM architected timers use an offset between their physical and
virtual counters. That offset should be configured by the bootloader
in CNTVOFF.

However, the A83t bootloader fails to do so, and we end up with an
undefined offset (which in our case is random), meaning that each CPU
will have a different time, which isn't working very well.

Fix that by setting the arm,cpu-registers-not-fw-configured that will
make Linux use the physical timers instead of the virtual ones. One
possible side effect would be that the virtualization features would
be disabled. However, due to the way the GIC has been integrated in
the system, it is already unusable so we're effectively not losing any
feature.

Signed-off-by: Myl?ne Josserand <mylene.josserand@free-electrons.com>
---
 arch/arm/boot/dts/sun8i-a83t.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/sun8i-a83t.dtsi b/arch/arm/boot/dts/sun8i-a83t.dtsi
index aa27ffb7db81..ddcd90ae3a73 100644
--- a/arch/arm/boot/dts/sun8i-a83t.dtsi
+++ b/arch/arm/boot/dts/sun8i-a83t.dtsi
@@ -121,6 +121,7 @@
 			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>,
 			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>,
 			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>;
+		arm,cpu-registers-not-fw-configured;
 	};
 
 	clocks {
-- 
2.11.0

  parent reply	other threads:[~2017-12-29 10:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-29 10:55 [PATCH v2 0/5] Sunxi: Add SMP support on A83T Mylène Josserand
2017-12-29 10:55 ` [PATCH v2 1/5] ARM: sun9i: Support SMP on A80 with Multi-Cluster Power Management (MCPM) Mylène Josserand
2017-12-29 13:47   ` Philippe Ombredanne
2017-12-29 10:55 ` [PATCH v2 2/5] ARM: sunxi: mcpm: Add support for A83T Mylène Josserand
2017-12-29 10:55 ` [PATCH v2 3/5] arm: dts: sun8i: a83t: Add registers needed for MCPM Mylène Josserand
2017-12-29 10:55 ` [PATCH v2 4/5] arm: dts: sun8i: a83t: Add CCI-400 node Mylène Josserand
2017-12-29 10:55 ` Mylène Josserand [this message]
2017-12-29 11:24 ` [PATCH v2 0/5] Sunxi: Add SMP support on A83T Mylene JOSSERAND

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