Hi Russell,

On Mon, Feb 28, 2011 at 01:33:42PM +0000, Will Deacon wrote:

quoted

The chained GPIO IRQ handler for the nomadik platform can be called
with the GIC as its host chip on the mach-ux500 machines.

This patch updates the code to use ->irq_eoi when it is available.

Cc: Rabin Vincent <redacted>
Signed-off-by: Will Deacon <redacted>
---
 arch/arm/plat-nomadik/gpio.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c
index 1e88ecb..51cc71b 100644
--- a/arch/arm/plat-nomadik/gpio.c
+++ b/arch/arm/plat-nomadik/gpio.c

@@ -538,6 +538,8 @@ static void nmk_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
 	}

 	host_chip->irq_unmask(&desc->irq_data);
+	if (host_chip->irq_eoi)
+		host_chip->irq_eoi(&desc->irq_data);

I notice in some you delete the irq_unmask, others you leave it.  Shouldn't
they all be similar?

It depends on whether or not the parent chip is always the GIC. In some cases
it can be a different IRQ chip, so we need to call the functions conditionally.
 

Maybe we do something like:

static inline void chained_irq_exit(struct irq_chip *chip, struct irq_desc *desc)
{
	if (chip->irq_eoi)
		chip->irq_eoi(&desc->irq_data);
	else
		chip->irq_unmask(&desc->irq_data);
}

to cover these exit paths in a common way?

Yes, that is cleaner and potentially less confusing. We'll also need an entry
function which will do something like:

	if (!chip->irq_eoi)
		chip->irq_mask(&desc->irq_data);

which does look pretty odd, so factoring it out (with a comment) will
make it a little clearer.

I'll see if I get any feedback about nomadik and msm and then post a v3
with the entry/exit functions.

Will