From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 5/5] ARM: picoxcell: implement watchdog restart
Date: Sun, 18 Dec 2011 08:13:27 +0000 [thread overview]
Message-ID: <20111218081327.GT14542@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1771411.xn5pEUbjJo@wuerfel>
On Sat, Dec 17, 2011 at 09:17:00PM +0100, Arnd Bergmann wrote:
> > +static void picoxcell_wdt_restart(char mode, const char *cmd)
> > +{
> > + /*
> > + * Configure the watchdog to reset with the shortest possible timeout
> > + * and give it chance to do the reset.
> > + */
> > + if (wdt_regs) {
> > + __raw_writel(WDT_CTRL_REG_EN_MASK, wdt_regs + WDT_CTRL_REG_OFFS);
> > + __raw_writel(0, wdt_regs + WDT_TIMEOUT_REG_OFFS);
> > + mdelay(500);
> > + }
> > +}
>
> Does this work if the real watchdog is still running, on a preemtible kernel?
>
> Also, please always use writel_relaxed instead of __raw_writel, and try to use
> msleep instead of mdelay by default. If msleep doesn't work here because it
> actually causes the system not to be reset, just add a comment.
Restarting can be called from atomic contexts, so any function which may
sleep must not be used. That include sioremap.
next prev parent reply other threads:[~2011-12-18 8:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-17 13:42 [PATCHv2 0/5] Misc picoxcell updates for 3.3 Jamie Iles
2011-12-17 13:42 ` [PATCHv2 1/5] ARM: picoxcell: remove mach/memory.h Jamie Iles
2011-12-17 13:42 ` [PATCHv2 2/5] ARM: picoxcell: don't reserve irq_descs Jamie Iles
2011-12-17 13:42 ` [PATCHv2 3/5] ARM: picoxcell: move io mappings to common.c Jamie Iles
2011-12-17 13:42 ` [PATCHv2 4/5] MAINTAINERS: add maintainer entry for Picochip picoxcell Jamie Iles
2011-12-17 13:42 ` [PATCHv2 5/5] ARM: picoxcell: implement watchdog restart Jamie Iles
2011-12-17 20:17 ` Arnd Bergmann
2011-12-18 0:05 ` Jamie Iles
2011-12-18 8:13 ` Russell King - ARM Linux [this message]
2011-12-18 9:41 ` Jamie Iles
2011-12-17 20:18 ` [PATCHv2 0/5] Misc picoxcell updates for 3.3 Arnd Bergmann
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