Re: request an irq without enabling? [Was: Re: [PATCH] gpio: mxs: implement get_direction callback]

[Richard Genoud <richard.genoud@xxxxxxxxx>]

2014-11-17 10:51 GMT+01:00 Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>:
> Hello,
>
> Sorry for the just sent unfinished mail. I pressed "send" instead of
> "reedit" after adding tglx to the recipients. Apart from the topic
> handled in this mail it's complete though.
>
> On Mon, Nov 17, 2014 at 10:11:25AM +0100, Janusz Użycki wrote:
>> W dniu 2014-11-17 o 09:28, Uwe Kleine-König pisze:
>> >I think mctrl_gpio_init should request the needed irqs, but not enable
>> >them. Not sure there is a corresponding request_irq variant for that.
>>
>> What would you propose?
> Thomas: Is there something available among the irq functions for that.
> The use case is that when probing an uart driver the modem control irqs
> should only be enabled when the enable_ms callback is called by the
> tty/serial framework. So we'd like to have something like
> request_irq_noenable. This way the enable_ms callback would just need
> to call enable_irq without first checking if the handler is already
> setup.
>
> The less nice alternatives are:
>
>  - use request_irq(..); disable_irq(); and handle the short window where
>    irqs are on but not yet desired.
>  - only request_irq in the enable_ms callback, and free_irq in
>    disable_ms.
>
> Any ideas?
In atmel_request_gpio_irq(), I used:
irq_set_status_flags(irq,IRQ_NOAUTOEN);
request_irq(...)

[ sorry for repeating myself, but our emails crossed themselves :) ]

Richard.
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