On Wed, Feb 18, 2009 at 12:17 AM, Matthias Kaehlcke
<[email protected]>wrote:
> Hi Ole,
>
> El Tue, Feb 17, 2009 at 05:51:35PM +0100 Ole Loots ha dit:
>
> > I want to handle an Interrupt on an ARM processor... (at91).
> >
> > The Interrupt is already handled by the module at91_timer (compiled into
> > kernel). the module registers it's interrupt this way:
> >
> > ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
> > IRQF_DISABLED | IRQF_SHARED,
> > "at91_rtc", pdev);
> >
> > Shouldn't it be possible to register a second interrupt handler for
> > AT91_ID_SYS? Because that is a shared Interrupt... the handler has to
> > check if it is the interrupt it has to handle, like that:
> >
> > rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
> > if (rtsr) { /* this interrupt is shared! Is it ours? */
> >
> > why can't I reqister another handler, this is how I do it:
> >
int *request_irq *(unsigned int irq, irq_handler_t handler, unsigned
long irqflags, const char * devname, void * dev_id);
Flag IRQF_SHARED for shared interrupt.
For last arg, dev_id, If your interrupt is shared you must pass a non NULL
dev_id as this is required when freeing the interrupt.
> > ret = request_irq(AT91_ID_SYS, timer_interrupt, SA_SHIRQ,
> > AD_IRQ_DEVICE_NAME, NULL);
> > if( ret )
> > {
> > printk(KERN_ERR "IRQ %d already claimed :(\n", AT91_ID_SYS);
> > return ret;
> > }
> >
> > that gives me just the message that the IRQ is already claimed.
> > Can somebody tell me that this is the right way to use shared IRQ's, or
> > am I totally wrong?
>
> i guess your problem is the missing (NULL) dev_id parameter. when
> using shared IRQs a unique device id must be passed, usually a pointer
> to the device data structure
>
> btw: you should use IRQF_SHARED instead of SA_SHIRQ, recent kernels
> don't define this symbol anymore
>
> --
> Matthias Kaehlcke
> Embedded Linux Engineer
> Barcelona
>
> El trabajo es el refugio de los que no tienen nada que hacer
> (Oscar Wilde)
> .''`.
> using free software / Debian GNU/Linux | http://debian.org : :' :
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>
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>
--
Thanks
Rizavan
