The decrementer on BookE acts as a level interrupt and doesn't
need to be re-triggered when going negative. It doesn't go
negative anyways (unless programmed to auto-reload with a
negative value) as it stops when reaching 0.
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
arch/powerpc/kernel/irq.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 77be3d0..fa6f385 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -159,8 +159,17 @@ notrace void raw_local_irq_restore(unsigned long en)
* use local_paca instead of get_paca() to avoid preemption checking.
*/
local_paca->hard_enabled = en;
+
+#ifndef CONFIG_BOOKE
+ /* On server, re-trigger the decrementer if it went negative since
+ * some processors only trigger on edge transitions of the sign bit.
+ *
+ * BookE has a level sensitive decrementer (latches in TSR) so we
+ * don't need that
+ */
if ((int)mfspr(SPRN_DEC) < 0)
mtspr(SPRN_DEC, 1);
+#endif /* CONFIG_BOOKE */
/*
* Force the delivery of pending soft-disabled interrupts on PS3.
--
1.6.3.3
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