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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-07-09 09:30:22 +0400 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-07-09 10:11:09 +0400 |
| commit | e8775d4aa17d70d123814e68a6a51bbea50e5c16 (patch) | |
| tree | 63d9dc7dd29165acfd941e5ac83cd80e8d55b57c | |
| parent | b9f1cd71dbf21a91fb7e2336a1d1ff18b97771e5 (diff) | |
| download | linux-e8775d4aa17d70d123814e68a6a51bbea50e5c16.tar.xz | |
powerpc/book3e: Don't re-trigger decrementer on lazy irq restore
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 <benh@kernel.crashing.org>
| -rw-r--r-- | 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 77be3d058a65..fa6f38525801 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. |