Re: [PATCH 1/3] ARM: at91: move at91 aic driver to drivers/irqchip

Thomas Petazzoni
2013-05-23T12:13:51Z

Dear Russell King - ARM Linux,

On Thu, 23 May 2013 11:18:25 +0100, Russell King - ARM Linux wrote:

> I notice arch/arm/mach-at91/pm.c makes use of some of the register
> definitions:
>
> at91_irq_suspend();
>
> pr_debug("AT91: PM - wake mask %08x, pm state %d\n",
> /* remember all the always-wake irqs */
> (at91_pmc_read(AT91_PMC_PCSR)
> | (1 << AT91_ID_FIQ)
> | (1 << AT91_ID_SYS)
> | (at91_extern_irq))
> & at91_aic_read(AT91_AIC_IMR),
> state);
>
> at91_irq_suspend() is in arch/arm/mach-at91/irq.c already, so there's no
> reason that fragment can't be moved there.

The problem is that the goal of the patch set is to move
arch/arm/mach-at91/irq.c into drivers/irqchip/.

However, if you move that chunk of code to drivers/irqchip/irq-at91.c,
you are using at91_pmc_read() which is defined in
arch/arm/mach-at91/include/mach/at91_pmc.h. So,
drivers/irqchip/irq-at91.c would have to include such an header file,
which is something we want to avoid since drivers/ code should not
include something in <mach/...>, as it breaks multiplatform kernels.

So, I'm afraid, simply moving this chunk of code in at91_irq_suspend()
doesn't make the thing any better.

Best regards,

Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.