From 8c92ba6c327ee5089dec1e92eaa82927bee63d6d Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 29 Mar 2012 15:57:18 -0400 Subject: arch/tile: add "nop" after "nap" to help GX idle power draw This avoids the hardware istream prefetcher doing unnecessary work. Signed-off-by: Chris Metcalf --- arch/tile/kernel/entry.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/tile/kernel/entry.S') diff --git a/arch/tile/kernel/entry.S b/arch/tile/kernel/entry.S index 431e9ae60488..ec91568df880 100644 --- a/arch/tile/kernel/entry.S +++ b/arch/tile/kernel/entry.S @@ -85,6 +85,7 @@ STD_ENTRY(cpu_idle_on_new_stack) /* Loop forever on a nap during SMP boot. */ STD_ENTRY(smp_nap) nap + nop /* avoid provoking the icache prefetch with a jump */ j smp_nap /* we are not architecturally guaranteed not to exit nap */ jrp lr /* clue in the backtracer */ STD_ENDPROC(smp_nap) @@ -105,5 +106,6 @@ STD_ENTRY(_cpu_idle) .global _cpu_idle_nap _cpu_idle_nap: nap + nop /* avoid provoking the icache prefetch with a jump */ jrp lr STD_ENDPROC(_cpu_idle) -- cgit v1.2.2