From: Andrew Lunn <andrew@lunn.ch>
To: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: linux@roeck-us.net, gregory.clement@bootlin.com,
jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org,
linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Wim Van Sebroeck <wim@linux-watchdog.org>,
devicetree@vger.kernel.org
Subject: Re: [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout
Date: Tue, 5 Mar 2019 01:57:10 +0100 [thread overview]
Message-ID: <20190305005710.GL26378@lunn.ch> (raw)
In-Reply-To: <20190304225152.26831-3-chris.packham@alliedtelesis.co.nz>
On Tue, Mar 05, 2019 at 11:51:52AM +1300, Chris Packham wrote:
> The orion watchdog can either reset the CPU or generate an interrupt.
> The interrupt would be useful for debugging as it provides panic()
> output about the watchdog expiry, however if the interrupt is used the
> watchdog can't reset the CPU in the event of being stuck in a loop with
> interrupts disabled or if the CPU is prevented from accessing memory
> (e.g. an unterminated DMA).
>
> All of the orion based CPU cores (at least back as far as Kirkwood) have
> spare timers that aren't currently used by the Linux kernel. We can use
> timer1 to provide a pre-timeout ahead of the watchdog timer and provide
> the possibility of gathering debug before the reset triggers.
Hi Chris
I had a quick look at other drivers implementing pre-timeout. They
seem to call watchdog_notify_pretimeout(). I don't see that here? What
happens when timer1 fires?
> @@ -169,38 +174,46 @@ static int armadaxp_wdt_clock_init(struct platform_device *pdev,
> }
>
> /* Enable the fixed watchdog clock input */
> - atomic_io_modify(dev->reg + TIMER_CTRL,
> - WDT_AXP_FIXED_ENABLE_BIT,
> - WDT_AXP_FIXED_ENABLE_BIT);
> + val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT;
> + atomic_io_modify(dev->reg + TIMER_CTRL, val, val);
>
> dev->clk_rate = clk_get_rate(dev->clk);
> +
> +
One blank line is sufficient,
> return 0;
> }
Andrew
next prev parent reply other threads:[~2019-03-05 0:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-11 2:29 [PATCH 0/3] getting more output from orion_wdt Chris Packham
2017-10-11 2:29 ` [PATCH 1/3] watchdog: orion: fix typo Chris Packham
2017-10-11 3:35 ` Guenter Roeck
2017-10-11 2:29 ` [PATCH 2/3] watchdog: orion: don't enable rstout if an interrupt is configured Chris Packham
2017-10-11 3:41 ` Guenter Roeck
2017-10-11 4:30 ` Chris Packham
2019-02-27 20:59 ` Chris Packham
2019-02-27 23:07 ` Guenter Roeck
2019-03-04 22:51 ` [PATCH 0/2] watchdog: orion_wdt: add pretimeout support Chris Packham
2019-03-04 22:51 ` [PATCH 1/2] watchdog: orion_wdt: remove orion_wdt_set_timeout Chris Packham
2019-03-05 17:17 ` Guenter Roeck
2019-03-04 22:51 ` [PATCH 2/2] watchdog: orion_wdt: use timer1 as a pretimeout Chris Packham
2019-03-05 0:57 ` Andrew Lunn [this message]
2019-03-05 1:26 ` Chris Packham
2019-03-05 2:09 ` Andrew Lunn
2019-03-05 17:27 ` Guenter Roeck
2017-10-11 2:29 ` [PATCH 3/3] ARM: mvebu: dts: connect interrupt for WD on armada-38x Chris Packham
2017-10-12 14:16 ` Gregory CLEMENT
2017-10-12 20:12 ` Chris Packham
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