intel_idle: disable Atom/Lincroft HW C-state auto-demotion

commit bfb53ccf1c734b1907df7189eef4c08489827951 upstream.

Just as we had to disable auto-demotion for NHM/WSM,
we need to do the same for Atom (Lincroft version).

In particular, auto-demotion will prevent Lincroft
from entering the S0i3 idle power saving state.

https://bugzilla.kernel.org/show_bug.cgi?id=25252

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 05c302c..0a6c5ef 100644 (file)
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -39,6 +39,7 @@
 #define MSR_NHM_SNB_PKG_CST_CFG_CTL    0x000000e2
 #define NHM_C3_AUTO_DEMOTE             (1UL << 25)
 #define NHM_C1_AUTO_DEMOTE             (1UL << 26)
+#define ATM_LNC_C6_AUTO_DEMOTE         (1UL << 25)
 
 #define MSR_MTRRcap                    0x000000fe
 #define MSR_IA32_BBL_CR_CTL            0x00000119

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index cba8617..d3d6ee1 100644 (file)
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -340,8 +340,12 @@ static int intel_idle_probe(void)
                break;
 
        case 0x1C:      /* 28 - Atom Processor */
+               cpuidle_state_table = atom_cstates;
+               break;
+
        case 0x26:      /* 38 - Lincroft Atom Processor */
                cpuidle_state_table = atom_cstates;
+               auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE;
                break;
 
        case 0x2A:      /* SNB */