On Wed, Feb 18, 2009 at 12:17 AM, Matthias Kaehlcke <matthias@xxxxxxxxxxxx> 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.
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)
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Thanks
Rizavan
