[PATCH RESEND v8 1/4] arm64: arch_timer: Add device tree binding for hisilicon-161010101 erratum
Ding Tianhong
dingtianhong at huawei.com
Thu Jan 19 03:46:43 PST 2017
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: Ding Tianhong <dingtianhong at huawei.com>
Acked-by: Rob Herring <robh at kernel.org>
---
Documentation/devicetree/bindings/arm/arch_timer.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt
index ad440a2..9116934 100644
--- a/Documentation/devicetree/bindings/arm/arch_timer.txt
+++ b/Documentation/devicetree/bindings/arm/arch_timer.txt
@@ -31,6 +31,14 @@ to deliver its interrupts via SPIs.
This also affects writes to the tval register, due to the implicit
counter read.
+- hisilicon,erratum-161010101 : A boolean property. Indicates the presence of
+ erratum 161010101, which says that reading the counter is unreliable unless
+ reading twice on the register and the value of the second read is larger
+ than the first by less than 32. If the verification is unsuccessful, then
+ discard the value of this read and repeat this procedure until the verification
+ is successful. 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
--
1.9.0
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