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From: sylvain.rochet@finsecur.com (Sylvain Rochet)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 1/2] dts: Documentation: AT91 Watchdog, explain what atmel, idle-halt property really do
Date: Sun, 18 Jan 2015 14:26:50 +0100	[thread overview]
Message-ID: <1421587611-32708-2-git-send-email-sylvain.rochet@finsecur.com> (raw)
In-Reply-To: <1421587611-32708-1-git-send-email-sylvain.rochet@finsecur.com>

atmel,idle-halt property should be used with care, it actually makes the
watchdog not counting when the CPU is in idle state, therefore the
watchdog reset time depends on mean CPU usage and will not reset at all
of the CPU stop working while it is in idle state, which is probably not
what you want.

Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
---
 Documentation/devicetree/bindings/watchdog/atmel-wdt.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
index f90e294..a4d8697 100644
--- a/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/atmel-wdt.txt
@@ -26,6 +26,11 @@ Optional properties:
 - atmel,disable : Should be present if you want to disable the watchdog.
 - atmel,idle-halt : Should be present if you want to stop the watchdog when
 	entering idle state.
+	CAUTION: This property should be used with care, it actually makes the
+	watchdog not counting when the CPU is in idle state, therefore the
+	watchdog reset time depends on mean CPU usage and will not reset at all
+	if the CPU stop working while it is in idle state, which is probably
+	not what you want.
 - atmel,dbg-halt : Should be present if you want to stop the watchdog when
 	entering debug state.
 
-- 
2.1.4

  reply	other threads:[~2015-01-18 13:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-17 21:49 [PATCH] AT91: DT: Watchdog, remove property idle halt by default Sylvain Rochet
2015-01-18  8:08 ` Boris Brezillon
2015-01-18 13:26   ` [PATCHv2 0/2] dts: AT91 " Sylvain Rochet
2015-01-18 13:26     ` Sylvain Rochet [this message]
2015-01-22 18:14       ` [PATCHv2 1/2] dts: Documentation: AT91 Watchdog, explain what atmel,idle-halt property really do Boris Brezillon
2015-01-18 13:26     ` [PATCHv2 2/2] dts: AT91 Watchdog, remove property idle halt by default Sylvain Rochet

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