[ 26/26] powerpc: Fix missing/delayed calls to irq_work

From: Greg Kroah-Hartman
Date: Tue Jun 18 2013 - 12:15:35 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

commit 230b3034793247f61e6a0b08c44cf415f6d92981 upstream.

When replaying interrupts (as a result of the interrupt occurring
while soft-disabled), in the case of the decrementer, we are exclusively
testing for a pending timer target. However we also use decrementer
interrupts to trigger the new "irq_work", which in this case would
be missed.

This change the logic to force a replay in both cases of a timer
boundary reached and a decrementer interrupt having actually occurred
while disabled. The former test is still useful to catch cases where
a CPU having been hard-disabled for a long time completely misses the
interrupt due to a decrementer rollover.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Tested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/kernel/irq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -162,7 +162,7 @@ notrace unsigned int __check_irq_replay(
* in case we also had a rollover while hard disabled
*/
local_paca->irq_happened &= ~PACA_IRQ_DEC;
- if (decrementer_check_overflow())
+ if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow())
return 0x900;

/* Finally check if an external interrupt happened */


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/