[PATCH v3 1/3] arm64: arch_timer: Add device tree binding for A-008585 erratum
Scott Wood
oss at buserror.net
Fri Jul 1 15:41:35 PDT 2016
This erratum describes a bug in logic outside the core, so MIDR can't be
used to identify its presence, and reading an SoC-specific revision
register from common arch timer code would be awkward. So, describe it
in the device tree.
Signed-off-by: Scott Wood <oss at buserror.net>
---
Documentation/devicetree/bindings/arm/arch_timer.txt | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt
index e774128..ef5fbe9 100644
--- a/Documentation/devicetree/bindings/arm/arch_timer.txt
+++ b/Documentation/devicetree/bindings/arm/arch_timer.txt
@@ -25,6 +25,12 @@ to deliver its interrupts via SPIs.
- always-on : a boolean property. If present, the timer is powered through an
always-on power domain, therefore it never loses context.
+- fsl,erratum-a008585 : A boolean property. Indicates the presence of
+ QorIQ erratum A-008585, which says that reading the counter is
+ unreliable unless the same value is returned by back-to-back reads.
+ This also affects writes to the tval register, due to the implicit
+ counter read.
+
** Optional properties:
- arm,cpu-registers-not-fw-configured : Firmware does not initialize
--
2.7.4
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