[PATCH] imx/gpio: Use handle_level_irq

[u.kleine-koenig@pengutronix.de (Uwe Kleine-König)]

Hello,

On Fri, Oct 23, 2009 at 07:27:08PM +0800, Richard Zhao wrote:
> 2009/10/21 Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>:
> > Hello Sascha,
> >
> > On Tue, Oct 20, 2009 at 10:13:03AM +0200, Sascha Hauer wrote:
> >> On Mon, Oct 19, 2009 at 10:19:28PM +0200, Uwe Kleine-K?nig wrote:
> >> > According to Russell King handle_edge_irq is only useful for "edge-based
> >> > inputs where the controller does not remember transitions with the input
> >> > masked."
> >> >
> >> > So using handle_edge_irq unconditionally for both edge and level irqs is
> >> > wrong. ?Testing showed that the controller does remember transitions
> >> > while the interrupt is masked. ?So use handle_level_irq unconditionally.
> >>
> >> As this fixes only rt kernels and we have no reports that something is
> >> not working on non rt kernels I suggest putting this into the next merge
> >> window.
> > The PMIC on pcm038 doesn't work anymore with handle_edge_irq since I
> > switched to using threaded irqs in the driver. ?But as this won't hit
> > mainline before the next merge window that is fine for me, too.
> 
> handle_level_irq may lost edge irq request. The controller won't
> change ISR when irq's masked.
> Why not decide to use handle_level_irq or handle_edge_irq in gpio_set_irq_type?
Have you read the commit log?  If yes, do you know a test case where
handle_level_irq fails to detect an edge irq when masked?

I did on a Phytec pcm038:

	set_irq_type(TRIGGER_RISING)
	mask(irq=119)
	provoke a rising edge on gpio55
	unmask(irq=119)

and after that the irq handler was entered.

Best regards
Uwe

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Pengutronix e.K.                              | Uwe Kleine-K?nig            |
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