From bdb48e4c7d0796850d4c1a24fe1386677e8a922c Mon Sep 17 00:00:00 2001
From: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz>
Date: Mon, 10 Dec 2018 11:27:39 +1300
Subject: [PATCH] dt-bindings: serial: 8250: Add rate limit for serial port
input overruns
When a serial port continuously experiences input overrun from
(1) continuous receive characters from remote and or (2) hardware
issues, its interrupt handler can preempt other tasks especially
when the system is busy (ie. boot up period). This can cause other
tasks to get starved of processing time from the CPU.
When this dts binding is enabled and input overrun on the serial port
is detected, serial port receive will be throttled to give some breathing
room for processing other tasks. Value provided will be in milliseconds.
&serial0{
overrun-throttle-ms = <500>;
};
Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Documentation/devicetree/bindings/serial/8250.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index aeb6db4e35c3b..da50321da34dd 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -51,6 +51,7 @@ Optional properties:
- tx-threshold: Specify the TX FIFO low water indication for parts with
programmable TX FIFO thresholds.
- resets : phandle + reset specifier pairs
+- overrun-throttle-ms : how long to pause uart rx when input overrun is encountered.
Note:
* fsl,ns16550:
--
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