Subject: Re: irq identification has changed from 2.6.10 to 2.6.23. an explanation is requested

From: Scott Wood <[email-masked]>
Date: Wed, 10 Oct 2007 15:47:32 -0500

Eno 3 Compton wrote:
> I had a driver working under 2.6.10 on a mpc8248. The kernel got changed 
> under me to 2.6.23. Now, when I call request_irq with SIU_INT_IRQ5, 
> which is defined in asm-powerpc/irq.h, and once compiled and worked 
> properly, I get compilation errors. The compiler can't find the symbol 
> definition because CONFIG_PPC_MERGE  is defined. I suspect the kernel 
> guys have migrated things to a new arrangement, which I've been unable 
> to discern.
> 
> An explanation or advice on where to find information about this would 
> be hugely appreciated.

Ideally, you should put whatever device you're trying to drive in the 
device tree, and use of_irq_to_resource() on the device node to find the 
virtual IRQ number.

Failing that, you can call irq_find_mapping(), but you'll need to either 
pass in the device node of the relevant interrupt controller, or call 
irq_set_default_host() -- but really, it's better to just use the device 
tree.

-Scott