On Mon, 11 Jun 2012, kuninori.morimoto.gx@xxxxxxxxxxx wrote:
> Hi all
>
> I noticed that mmc_cd_gpio_request() failed on request_threaded_irq().
> Now, I'm using v3.5-rc2 kernel.
>
> current ${LINUX}/drivers/mmc/core/cd-gpio.c :: mmc_cd_gpio_request() uses
>
> request_threaded_irq(irq, NULL, mmc_cd_gpio_irqt,
> IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> cd->label, host);
>
> It doesn't have hander (2nd is NULL), and flag doesn't have IRQF_ONESHOT.
> Then, it run request_threaded_irq() -> __setup_irq()
> and, it got this error.
>
> pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
> irq);
>
> I'm not sure detail of it, but maybe from this commit
>
> -------------------------------------------
> commit 1c6c69525b40eb76de8adf039409722015927dc3
> Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Date: Thu Apr 19 10:35:17 2012 +0200
>
> genirq: Reject bogus threaded irq requests
Also see this thread: https://lkml.org/lkml/2012/6/12/151
For now you can add an IRQF_ONESHOT flag to the call.
Thanks
Guennadi
>
> Requesting a threaded interrupt without a primary handler and without
> IRQF_ONESHOT set is dangerous.
>
> The core will use the default primary handler for it, which merily
> wakes the thread. For a level type interrupt this results in an
> interrupt storm, because the interrupt line is reenabled after the
> primary handler runs. The device has still the line asserted, which
> brings us back into the primary handler.
> ...
> ------------------------------------------
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---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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