On Monday, January 30, 2012 06:15:02 PM Uwe Kleine-K?nig wrote:

On Mon, Jan 30, 2012 at 09:33:23AM +1100, Marc Reilly wrote:

quoted

This acks any existing pending ADCDONE irqs before requesting one for the
new conversion, rather than after.

Signed-off-by: Marc Reilly <redacted>
---

 drivers/mfd/mc13xxx-core.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
index 1fd265d..8cb83ef 100644
--- a/drivers/mfd/mc13xxx-core.c
+++ b/drivers/mfd/mc13xxx-core.c

@@ -561,9 +561,9 @@ int mc13xxx_adc_do_conversion(struct mc13xxx

*mc13xxx, unsigned int mode,

 	}
 	
 	dev_dbg(mc13xxx->dev, "%s: request irq\n", __func__);

+	mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_ADCDONE);

 	mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_ADCDONE,
 	
 			mc13xxx_handler_adcdone, __func__, &adcdone_data);

-	mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_ADCDONE);

 	mc13xxx_reg_write(mc13xxx, MC13XXX_ADC0, adc0);
 	mc13xxx_reg_write(mc13xxx, MC13XXX_ADC1, adc1);

hmm, I wonder if the irq should be acked if it's not requested. The code
doesn't do error checking, but consider mc13xxx_irq_request fails
because the irq is already requested by someone else. Then acking before
requesting is wrong, isn't it?

I see your point.

Maybe irq_request should ack the irq or
maybe better introduce a function mc13xxx_irq_request_and_ack that acks
only if the request part is OK?

I'd say that just acking in mc13xxx_irq_request is good enough. Ack happens 
after the request, before unmasking. Do you see any specific need for handling 
a pre-existing interrupt?

Cheers,
Marc