[patch-mm 08/23] i386: PIT stop only, when in periodic or oneshot mode

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: i386-add-another-pit-quirk.patch --]
[-- Type: text/plain, Size: 1004 bytes --]

The patch is necessary on one of my boxen, where programming the stop
sequence twice leads to PIT malfunction.

Sigh !

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/i386/kernel/i8253.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Index: linux-2.6.22-rc4-mm/arch/i386/kernel/i8253.c
===================================================================
--- linux-2.6.22-rc4-mm.orig/arch/i386/kernel/i8253.c	2007-06-10 10:44:38.000000000 +0200
+++ linux-2.6.22-rc4-mm/arch/i386/kernel/i8253.c	2007-06-10 10:44:38.000000000 +0200
@@ -48,9 +48,12 @@ static void init_pit_timer(enum clock_ev
 
 	case CLOCK_EVT_MODE_SHUTDOWN:
 	case CLOCK_EVT_MODE_UNUSED:
-		outb_p(0x30, PIT_MODE);
-		outb_p(0, PIT_CH0);	/* LSB */
-		outb_p(0, PIT_CH0);	/* MSB */
+		if (evt->mode == CLOCK_EVT_MODE_PERIODIC ||
+		    evt->mode == CLOCK_EVT_MODE_ONESHOT) {
+			outb_p(0x30, PIT_MODE);
+			outb_p(0, PIT_CH0);
+			outb_p(0, PIT_CH0);
+		}
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:

--