From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 5/6] watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND
Date: Fri, 6 Mar 2015 13:10:26 +0000 [thread overview]
Message-ID: <20150306131025.GH8700@leverpostej> (raw)
In-Reply-To: <CAJZ5v0jA-hRUnP_+mOdFw7vN7CGZ4o0FjUVu81rq7foi92f63g@mail.gmail.com>
> >> > We seem to be conflating some related properties:
> >> >
> >> > [a] The IRQ will be left unmasked.
> >> > [b] The IRQ will be handled immediately when taken.
> >> > [c] The IRQ will wake the system from suspend.
[...]
> > Considering that the use-case of a watchdog is to alert us to something
> > going hideously wrong in the kernel, we want to handle the IRQ after
> > executing the smallest amount of kernel code possible. For that, they
> > need to have their handlers to be called "immediately" outside of the
> > arch_suspend_disable_irqs() ... arch_suspend_enable_irqs() window, and
> > need to be enabled during suspend to attempt to catch bad wakeup device
> > configuration.
> >
> > I think it's possible (assuming the caveats on [b] above) to provide
> > [a,b,c] for this case.
>
> OK
>
> But in this case the request_irq() passing IRQF_NO_SUSPEND *and* requiring
> enable_irq_wake() in addition to that needs a big fat comment explaining the
> whole thing or we'll forget about the gory details at one point and no one will
> know what's going on in there.
Agreed.
I'd expect an IRQF_SW_WATCHDOG or something to that effect should also
be required for that case.
Thanks,
Mark.
next prev parent reply other threads:[~2015-03-06 13:10 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-02 9:18 [PATCH v2 0/6] ARM: at91: fix irq_pm_install_action WARNING Boris Brezillon
2015-03-02 9:18 ` [PATCH v2 1/6] PM / wakeup: export pm_system_wakeup symbol Boris Brezillon
2015-03-02 9:18 ` [PATCH v2 2/6] rtc: at91sam9: rework wakeup and interrupt handling Boris Brezillon
2015-03-04 18:23 ` Mark Rutland
2015-03-02 9:18 ` [PATCH v2 3/6] rtc: at91rm9200: " Boris Brezillon
2015-03-02 9:18 ` [PATCH v2 4/6] clk: at91: implement suspend/resume for the PMC irqchip Boris Brezillon
2015-03-09 22:34 ` Mike Turquette
2015-03-02 9:18 ` [PATCH v2 5/6] watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND Boris Brezillon
2015-03-02 14:10 ` Guenter Roeck
2015-03-04 18:38 ` Mark Rutland
2015-03-04 21:41 ` Rafael J. Wysocki
2015-03-05 10:57 ` Mark Rutland
2015-03-05 15:10 ` Rafael J. Wysocki
2015-03-05 16:32 ` Mark Rutland
2015-03-06 0:29 ` Rafael J. Wysocki
2015-03-06 11:06 ` Mark Rutland
2015-03-06 12:39 ` Rafael J. Wysocki
2015-03-06 13:10 ` Mark Rutland [this message]
2015-03-07 9:12 ` Peter Zijlstra
2015-03-07 9:06 ` Peter Zijlstra
2015-03-05 8:53 ` Boris Brezillon
2015-03-05 10:53 ` Mark Rutland
2015-03-05 11:17 ` Boris Brezillon
2015-03-05 11:31 ` Boris Brezillon
2015-03-05 11:53 ` Mark Rutland
2015-03-07 9:18 ` Peter Zijlstra
2015-03-07 10:20 ` Sylvain Rochet
2015-03-07 10:39 ` Pavel Machek
2015-03-07 10:59 ` Sylvain Rochet
2015-03-07 11:06 ` Alexandre Belloni
2015-03-07 11:29 ` Pavel Machek
2015-03-07 11:46 ` Sylvain Rochet
2015-03-08 1:12 ` Rafael J. Wysocki
2015-03-09 7:55 ` Alexandre Belloni
2015-03-09 14:30 ` Rafael J. Wysocki
2015-03-10 21:33 ` Alexandre Belloni
2015-03-10 22:31 ` Rafael J. Wysocki
2015-03-10 22:33 ` Alexandre Belloni
2015-03-11 1:03 ` Rafael J. Wysocki
2015-03-11 7:33 ` Boris Brezillon
2015-03-08 1:11 ` Rafael J. Wysocki
2015-03-11 8:38 ` Boris Brezillon
2015-03-11 11:17 ` Nicolas Ferre
2015-03-02 9:18 ` [PATCH v2 6/6] tty: serial: atmel: rework interrupt and wakeup handling Boris Brezillon
2015-03-03 8:56 ` [PATCH v2 0/6] ARM: at91: fix irq_pm_install_action WARNING Alexandre Belloni
2015-03-03 15:35 ` Nicolas Ferre
2015-03-04 1:43 ` Rafael J. Wysocki
2015-03-04 18:43 ` Mark Rutland
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