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authorThomas Gleixner <tglx@linutronix.de>2007-07-21 04:37:38 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-21 17:49:15 -0700
commit7671988b9cd31daf53fd38f8e75c8b881324842b (patch)
treefc4aa3a4cf61f73ee5c6025aff9959ad005ef3b8
parent82644459c592a28a3eab682f9b88d81019ddfe8b (diff)
i386: PIT stop only, when in periodic or oneshot mode
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> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/i386/kernel/i8253.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/i386/kernel/i8253.c b/arch/i386/kernel/i8253.c
index 931eabe1e560..bde249dda94d 100644
--- a/arch/i386/kernel/i8253.c
+++ b/arch/i386/kernel/i8253.c
@@ -47,9 +47,12 @@ static void init_pit_timer(enum clock_event_mode mode,
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: