From: Guenter Roeck <linux@roeck-us.net>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Bruno Thomsen <bruno.thomsen@gmail.com>,
linux-watchdog@vger.kernel.org, linux-rtc@vger.kernel.org,
open list <linux-kernel@vger.kernel.org>,
Lars Alex Pedersen <laa@kamstrup.com>,
Bruno Thomsen <bth@kamstrup.com>,
NXP Linux Team <linux-imx@nxp.com>
Subject: Re: watchdog: pcf2127: systemd fails on 5.11
Date: Wed, 24 Feb 2021 07:25:29 -0800 [thread overview]
Message-ID: <20210224152529.GA242356@roeck-us.net> (raw)
In-Reply-To: <YDZp/u+fO/8HX8qo@piout.net>
On Wed, Feb 24, 2021 at 04:00:14PM +0100, Alexandre Belloni wrote:
> Hi,
>
> On 24/02/2021 15:55:00+0100, Bruno Thomsen wrote:
> > You could be right about that, I don't think the watchdog feature should
> > be available for use if the alarm feature is enabled due to how CTRL2
> > register behaves.
> >
> > The hardware I am testing on is a custom board, but it's actually
> > possible to get a Raspberry Pi module called RasClock that has
> > the chip.
> >
>
> I have an eval board for the PCF2127 (and PCF2129), the OM13513.
>
> > I will test some locking around WD_VAL register access as that is used
> > in pcf2127_wdt_ping function.
> >
> > My initial test shows that spin_lock_irqsave around regmap calls are not
> > a good idea as it result in:
> > BUG: scheduling while atomic: watchdog/70/0x00000002
> > BUG: scheduling while atomic: systemd/1/0x00000002
> >
>
> The issue is not only regmap but the fact that i2C and spi accesses are
> allowed to sleep.
>
Correct, those would have to be mutexes.
Thanks,
Guenter
prev parent reply other threads:[~2021-02-24 15:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-18 12:35 watchdog: pcf2127: systemd fails on 5.11 Bruno Thomsen
2021-02-22 22:43 ` Guenter Roeck
2021-02-24 14:55 ` Bruno Thomsen
2021-02-24 15:00 ` Alexandre Belloni
2021-02-24 15:25 ` Guenter Roeck [this message]
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