[139/141] powerpc: Fix missing/delayed calls to irq_work

Steven Rostedt
2013-07-03T19:19:51Z

[-- Attachment #1: 0139-powerpc-Fix-missing-delayed-calls-to-irq_work.patch --]
[-- Type: text/plain, Size: 1638 bytes --]

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

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

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[ Upstream commit 230b3034793247f61e6a0b08c44cf415f6d92981 ]

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.

CC: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/powerpc/kernel/irq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 1f017bb..86cb68e 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -162,7 +162,7 @@ notrace unsigned int __check_irq_replay(void)
* 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 */
--
1.7.10.4