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| author | Len Brown <len.brown@intel.com> | 2014-07-31 21:21:24 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2014-08-15 23:06:14 +0200 |
| commit | 8c058d53f6f2eb0b9cd3bc4ce5c053a64dded671 (patch) | |
| tree | fb657c7092c97ce7452746008c2894ec17e481ae | |
| parent | Linux 3.16 (diff) | |
| download | linux-8c058d53f6f2eb0b9cd3bc4ce5c053a64dded671.tar.xz linux-8c058d53f6f2eb0b9cd3bc4ce5c053a64dded671.zip | |
intel_idle: Disable Baytrail Core and Module C6 auto-demotion
Power efficiency improves on Baytrail (Intel Atom Processor E3000)
when Linux disables C6 auto-demotion.
Based on work by Srinidhi Kasagar <srinidhi.kasagar@intel.com>.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
| -rw-r--r-- | arch/x86/include/uapi/asm/msr-index.h | 3 | ||||
| -rw-r--r-- | drivers/idle/intel_idle.c | 7 |
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h index fcf2b3ae1bf0..4a7aecd2ea13 100644 --- a/arch/x86/include/uapi/asm/msr-index.h +++ b/arch/x86/include/uapi/asm/msr-index.h @@ -149,6 +149,9 @@ #define MSR_CORE_C1_RES 0x00000660 +#define MSR_CC6_DEMOTION_POLICY_CONFIG 0x00000668 +#define MSR_MC6_DEMOTION_POLICY_CONFIG 0x00000669 + #define MSR_AMD64_MC0_MASK 0xc0010044 #define MSR_IA32_MCx_CTL(x) (MSR_IA32_MC0_CTL + 4*(x)) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 4d140bbbe100..2d23cf8279f0 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -89,6 +89,7 @@ struct idle_cpu { * Indicate which enable bits to clear here. */ unsigned long auto_demotion_disable_flags; + bool byt_auto_demotion_disable_flag; bool disable_promotion_to_c1e; }; @@ -613,6 +614,7 @@ static const struct idle_cpu idle_cpu_snb = { static const struct idle_cpu idle_cpu_byt = { .state_table = byt_cstates, .disable_promotion_to_c1e = true, + .byt_auto_demotion_disable_flag = true, }; static const struct idle_cpu idle_cpu_ivb = { @@ -814,6 +816,11 @@ static int __init intel_idle_cpuidle_driver_init(void) if (icpu->auto_demotion_disable_flags) on_each_cpu(auto_demotion_disable, NULL, 1); + if (icpu->byt_auto_demotion_disable_flag) { + wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0); + wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0); + } + if (icpu->disable_promotion_to_c1e) /* each-cpu is redundant */ on_each_cpu(c1e_promotion_disable, NULL, 1); |