Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=91bc51d8a10b00d8233dd5b6f07d7eb40828b87d
Commit: 91bc51d8a10b00d8233dd5b6f07d7eb40828b87d
Parent: c2ec21c5c8f15c079c209f403d582f3134785060
Author: Russell King <[EMAIL PROTECTED]>
AuthorDate: Thu Nov 8 23:35:46 2007 +0000
Committer: Russell King <[EMAIL PROTECTED]>
CommitDate: Thu Nov 8 23:35:46 2007 +0000
[ARM] pxa: fix one-shot timer mode
One-shot timer mode on PXA has various bugs which prevent kernels
build with NO_HZ enabled booting. They end up spinning on a
permanently asserted timer interrupt because we don't properly
clear it down - clearing the OIER bit does not stop the pending
interrupt status. Fix this in the set_mode handler as well.
Moreover, the code which sets the next expiry point may race with
the hardware, and we might not set the match register sufficiently
in the future. If we encounter that situation, return -ETIME so
the generic time code retries.
Acked-by: Thomas Gleixner <[EMAIL PROTECTED]>
Acked-by: Nicolas Pitre <[EMAIL PROTECTED]>
Signed-off-by: Russell King <[EMAIL PROTECTED]>
---
arch/arm/mach-pxa/time.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index a2d45d7..fbfa192 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -68,6 +68,7 @@ pxa_ost0_interrupt(int irq, void *dev_id)
if (c->mode == CLOCK_EVT_MODE_ONESHOT) {
/* Disarm the compare/match, signal the event. */
OIER &= ~OIER_E0;
+ OSSR = OSSR_M0;
c->event_handler(c);
} else if (c->mode == CLOCK_EVT_MODE_PERIODIC) {
/* Call the event handler as many times as necessary
@@ -100,9 +101,9 @@ pxa_ost0_interrupt(int irq, void *dev_id)
* anything that might put us "very close".
*/
#define MIN_OSCR_DELTA 16
- do {
+ do {
OSSR = OSSR_M0;
- next_match = (OSMR0 += LATCH);
+ next_match = (OSMR0 += LATCH);
c->event_handler(c);
} while (((signed long)(next_match - OSCR) <= MIN_OSCR_DELTA)
&& (c->mode == CLOCK_EVT_MODE_PERIODIC));
@@ -114,14 +115,16 @@ pxa_ost0_interrupt(int irq, void *dev_id)
static int
pxa_osmr0_set_next_event(unsigned long delta, struct clock_event_device *dev)
{
- unsigned long irqflags;
+ unsigned long flags, next, oscr;
- raw_local_irq_save(irqflags);
- OSMR0 = OSCR + delta;
- OSSR = OSSR_M0;
+ raw_local_irq_save(flags);
OIER |= OIER_E0;
- raw_local_irq_restore(irqflags);
- return 0;
+ next = OSCR + delta;
+ OSMR0 = next;
+ oscr = OSCR;
+ raw_local_irq_restore(flags);
+
+ return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
}
static void
@@ -132,15 +135,16 @@ pxa_osmr0_set_mode(enum clock_event_mode mode, struct
clock_event_device *dev)
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
raw_local_irq_save(irqflags);
- OSMR0 = OSCR + LATCH;
OSSR = OSSR_M0;
OIER |= OIER_E0;
+ OSMR0 = OSCR + LATCH;
raw_local_irq_restore(irqflags);
break;
case CLOCK_EVT_MODE_ONESHOT:
raw_local_irq_save(irqflags);
OIER &= ~OIER_E0;
+ OSSR = OSSR_M0;
raw_local_irq_restore(irqflags);
break;
@@ -149,6 +153,7 @@ pxa_osmr0_set_mode(enum clock_event_mode mode, struct
clock_event_device *dev)
/* initializing, released, or preparing for suspend */
raw_local_irq_save(irqflags);
OIER &= ~OIER_E0;
+ OSSR = OSSR_M0;
raw_local_irq_restore(irqflags);
break;
-
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