Hi,

On 07/19/2013 04:26 PM, Felipe Balbi wrote:

Hi,

[...]
please don't remove this code. It'll be good to have this around when we
move the driver to threaded IRQs without IRQF_ONESHOT. In fact, it would
be very simple to implement such a change, wanna take it up ?

It should be doable in few patches:

1) switch over to request_threaded_irq()

	just blind move to a thread, without hardirq handler, so
	IRQF_ONESHOT is mandatory.

2) add hardirq handler

	read IRQSTATUS to check if our device has generated IRQs
	returning IRQ_WAKE_THREAD if true

3) move 'IRQ masking logic' to hardirq handler, before returning
IRQ_WAKE_THREAD

	this will let you remove IRQF_ONESHOT

4) finally remove IRQF_ONESHOT

	this makes sure that IRQs aren't kept disabled until we have
	time to iterate over the entire keypad matrix. Only the keypad
	IRQ will be masked.

Ok, but why we need to remove IRQF_ONESHOT flag for omap keypad driver?

The keypad IRQ isn't shared IRQ and in our case hardirq handler will 
always return IRQ_WAKE_THREAD like default irq_default_primary_handler 
do. With IRQF_ONESHOT flag IRQ line will be masked until the threaded
handler finished, but there is only keypad on this line.

I tested two versions:
the first one - just threaded IRQs with IRQF_ONESHOT and without 
specific hardirq handler.
the second version - threaded IRQs without IRQF_ONESHOT as you described.
Both versions was successfully tested on Blaze's keypad.