Thread (7 messages) 7 messages, 3 authors, 2013-07-22

Re: [PATCH 2/2] Input: omap-keypad: Cleanup - remove unnecessary IRQ enabling/disabling

From: Felipe Balbi <hidden>
Date: 2013-07-19 13:26:58
Also in: linux-omap, lkml

Hi,

On Fri, Jul 19, 2013 at 04:03:47PM +0300, Illia Smyrnov wrote:
quoted hunk ↗ jump to hunk
From: Illia Smyrnov <redacted>

Remove unnecessary IRQ enabling/disabling for certain keyboard events.

Signed-off-by: Illia Smyrnov <redacted>
---
 drivers/input/keyboard/omap4-keypad.c |   15 ++++-----------
 1 files changed, 4 insertions(+), 11 deletions(-)
diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
index c727548..73813b6 100644
--- a/drivers/input/keyboard/omap4-keypad.c
+++ b/drivers/input/keyboard/omap4-keypad.c
@@ -121,10 +121,6 @@ static irqreturn_t omap4_keypad_interrupt(int irq, void *dev_id)
 	unsigned int col, row, code, changed;
 	u32 *new_state = (u32 *) key_state;
 
-	/* Disable interrupts */
-	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
-			 OMAP4_VAL_IRQDISABLE);
-
 	*new_state = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
 	*(new_state + 1) = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
 
@@ -154,11 +150,6 @@ static irqreturn_t omap4_keypad_interrupt(int irq, void *dev_id)
 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
 			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
 
-	/* enable interrupts */
-	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
-		OMAP4_DEF_IRQENABLE_EVENTEN |
-				OMAP4_DEF_IRQENABLE_LONGKEY);
-
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.

-- 
balbi

Attachments

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help