diff options
| author | Olof Johansson <olof@lixom.net> | 2006-10-04 23:41:41 -0500 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2006-10-16 16:32:25 +1000 |
| commit | 5b43d20a4d12d94f258bbbca5fa4df8ff8a17848 (patch) | |
| tree | 83b72628e99850fde1a49c435cbeee6e5750f942 /arch/powerpc/kernel/cpu_setup_ppc970.S | |
| parent | d04c56f73c30a5e593202ecfcf25ed43d42363a2 (diff) | |
[POWERPC] powerpc: Enable DEEPNAP power savings mode on 970MP
Without this patch, on an idle system I get:
cpu-power-0:21.638
cpu-power-1:27.102
cpu-power-2:29.343
cpu-power-3:25.784
Total: 103.8W
With this patch:
cpu-power-0:11.730
cpu-power-1:17.185
cpu-power-2:18.547
cpu-power-3:17.528
Total: 65.0W
If I lower HZ to 100, I can get it as low as:
cpu-power-0:10.938
cpu-power-1:16.021
cpu-power-2:17.245
cpu-power-3:16.145
Total: 60.2W
Another (older) Quad G5 went from 54W to 39W at HZ=250.
Coming back out of Deep Nap takes 40-70 cycles longer than coming back
from just Nap (which already takes quite a while). I don't think it'll
be a performance issue (interrupt latency on an idle system), but in
case someone does measurements feel free to report them.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/cpu_setup_ppc970.S')
| -rw-r--r-- | arch/powerpc/kernel/cpu_setup_ppc970.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/cpu_setup_ppc970.S b/arch/powerpc/kernel/cpu_setup_ppc970.S index 652594891d5..bf118c38575 100644 --- a/arch/powerpc/kernel/cpu_setup_ppc970.S +++ b/arch/powerpc/kernel/cpu_setup_ppc970.S @@ -83,6 +83,22 @@ _GLOBAL(__setup_cpu_ppc970) rldimi r0,r11,52,8 /* set NAP and DPM */ li r11,0 rldimi r0,r11,32,31 /* clear EN_ATTN */ + b load_hids /* Jump to shared code */ + + +_GLOBAL(__setup_cpu_ppc970MP) + /* Do nothing if not running in HV mode */ + mfmsr r0 + rldicl. r0,r0,4,63 + beqlr + + mfspr r0,SPRN_HID0 + li r11,0x15 /* clear DOZE and SLEEP */ + rldimi r0,r11,52,6 /* set DEEPNAP, NAP and DPM */ + li r11,0 + rldimi r0,r11,32,31 /* clear EN_ATTN */ + +load_hids: mtspr SPRN_HID0,r0 mfspr r0,SPRN_HID0 mfspr r0,SPRN_HID0 |