[PATCH] irq: Export symbol no_action()

[PATCH] irq: Export symbol no_action()

[Alexander Shiyan]

This will allow to use dummy IRQ handler no_action() from
drivers compiled as module. For example, dummy handler is could
be used for drivers that use ARM FIQ interrupts.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
 kernel/irq/handle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index bfec453..e8ddcbf 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -41,6 +41,7 @@ irqreturn_t no_action(int cpl, void *dev_id)
 {
 	return IRQ_NONE;
 }
+EXPORT_SYMBOL(no_action);
 
 static void warn_no_thread(unsigned int irq, struct irqaction *action)
 {
-- 
1.8.3.2

Re: [PATCH] irq: Export symbol no_action()

[Thomas Gleixner]

On Sat, 1 Mar 2014, Alexander Shiyan wrote:

> This will allow to use dummy IRQ handler no_action() from
> drivers compiled as module. For example, dummy handler is could
> be used for drivers that use ARM FIQ interrupts.

And why exactly requires a driver which uses ARM FIQ interrupts the
no_action implementation?
 
> @@ -41,6 +41,7 @@ irqreturn_t no_action(int cpl, void *dev_id)
>  {
>  	return IRQ_NONE;
>  }
> +EXPORT_SYMBOL(no_action);

EXPORT_SYMBOL_GPL if at all.

Thanks,

	tglx

Re: [PATCH] irq: Export symbol no_action()

[Alexander Shiyan]

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Вторник,  4 марта 2014, 12:05 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> On Sat, 1 Mar 2014, Alexander Shiyan wrote:
> 
> > This will allow to use dummy IRQ handler no_action() from
> > drivers compiled as module. For example, dummy handler is could
> > be used for drivers that use ARM FIQ interrupts.
> 
> And why exactly requires a driver which uses ARM FIQ interrupts the
> no_action implementation?

FIQ Interrupt handler is not used in this function. In FIQ case this is just a
dummy declaration. Real handler is assigned by using the set_fiq_handler().

> > @@ -41,6 +41,7 @@ irqreturn_t no_action(int cpl, void *dev_id)
> >  {
> >  	return IRQ_NONE;
> >  }
> > +EXPORT_SYMBOL(no_action);
> 
> EXPORT_SYMBOL_GPL if at all.

v2?

---
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Re: [PATCH] irq: Export symbol no_action()

[Thomas Gleixner]

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On Tue, 4 Mar 2014, Alexander Shiyan wrote:

> Вторник,  4 марта 2014, 12:05 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> > On Sat, 1 Mar 2014, Alexander Shiyan wrote:
> > 
> > > This will allow to use dummy IRQ handler no_action() from
> > > drivers compiled as module. For example, dummy handler is could
> > > be used for drivers that use ARM FIQ interrupts.
> > 
> > And why exactly requires a driver which uses ARM FIQ interrupts the
> > no_action implementation?
>
 
> FIQ Interrupt handler is not used in this function. In FIQ case this
> is just a dummy declaration. Real handler is assigned by using the
> set_fiq_handler().

Why do you need a dummy declaration at all?

set_fiq_handler() is completely detached from the generic interrupt
subsystem.

Thanks,

	tglx

Re: [PATCH] irq: Export symbol no_action()

[Alexander Shiyan]

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+сс Arnd Bergmann

Вторник,  4 марта 2014, 16:46 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> On Tue, 4 Mar 2014, Alexander Shiyan wrote:
> 
> > Вторник,  4 марта 2014, 12:05 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> > > On Sat, 1 Mar 2014, Alexander Shiyan wrote:
> > > 
> > > > This will allow to use dummy IRQ handler no_action() from
> > > > drivers compiled as module. For example, dummy handler is could
> > > > be used for drivers that use ARM FIQ interrupts.
> > > 
> > > And why exactly requires a driver which uses ARM FIQ interrupts the
> > > no_action implementation?
> >
>  
> > FIQ Interrupt handler is not used in this function. In FIQ case this
> > is just a dummy declaration. Real handler is assigned by using the
> > set_fiq_handler().
> 
> Why do you need a dummy declaration at all?
> 
> set_fiq_handler() is completely detached from the generic interrupt
> subsystem.

Some limitations of hardware, such as bit interleaving for normal and
FIQ interrupts for mask/status registers, led to the implement single
driver for interrupt handling.
As a result, all interrupts can be described equally, and single mechanism
is used for the request/free and enable/disable.
Correct me if I'm wrong. Driver that implements it, resent several times
and expect comments within 3 months [1], you are the only one person,
Thomas, specified as maintainer for this subsystem.
I repeat, if I'm wrong in the implementation, let's fix this.

[1]: http://marc.info/?l=linux-arm-kernel&m=139132855024699

Thanks.
---
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Re: [PATCH] irq: Export symbol no_action()

[Thomas Gleixner]

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On Tue, 4 Mar 2014, Alexander Shiyan wrote:
> +сс Arnd Bergmann
> 
> Вторник,  4 марта 2014, 16:46 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> > On Tue, 4 Mar 2014, Alexander Shiyan wrote:
> > 
> > > Вторник,  4 марта 2014, 12:05 +01:00 от Thomas Gleixner <tglx@linutronix.de>:
> > > > On Sat, 1 Mar 2014, Alexander Shiyan wrote:
> > > > 
> > > > > This will allow to use dummy IRQ handler no_action() from
> > > > > drivers compiled as module. For example, dummy handler is could
> > > > > be used for drivers that use ARM FIQ interrupts.
> > > > 
> > > > And why exactly requires a driver which uses ARM FIQ interrupts the
> > > > no_action implementation?
> > >
> >  
> > > FIQ Interrupt handler is not used in this function. In FIQ case this
> > > is just a dummy declaration. Real handler is assigned by using the
> > > set_fiq_handler().
> > 
> > Why do you need a dummy declaration at all?
> > 
> > set_fiq_handler() is completely detached from the generic interrupt
> > subsystem.
> 
> Some limitations of hardware, such as bit interleaving for normal and
> FIQ interrupts for mask/status registers, led to the implement single
> driver for interrupt handling.
> As a result, all interrupts can be described equally, and single mechanism
> is used for the request/free and enable/disable.
> Correct me if I'm wrong. Driver that implements it, resent several times
> and expect comments within 3 months [1], you are the only one person,
> Thomas, specified as maintainer for this subsystem.
> I repeat, if I'm wrong in the implementation, let's fix this.
> 
> [1]: http://marc.info/?l=linux-arm-kernel&m=139132855024699

Lemme find this and review it.

Thanks,

	tglx