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authorLen Brown <len.brown@intel.com>2010-07-22 18:18:28 -0400
committerLen Brown <len.brown@intel.com>2010-07-22 18:18:28 -0400
commit4a973f2495fba8775d1c408b3ee7f2c19b19f13f (patch)
tree302484851e44029a208cce8c79294a82f25561d9 /arch/x86
parentbe48b11573952b467676b24de87d637e33339e7d (diff)
parentd3e7e99f2faf9f44ec0a3379f735b41c9173dfa1 (diff)
Merge branch 'bugzilla-15886' into release
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/acpi/cstate.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index 2e837f5080f..fb7a5f052e2 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -145,6 +145,15 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu,
percpu_entry->states[cx->index].eax = cx->address;
percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK;
}
+
+ /*
+ * For _CST FFH on Intel, if GAS.access_size bit 1 is cleared,
+ * then we should skip checking BM_STS for this C-state.
+ * ref: "Intel Processor Vendor-Specific ACPI Interface Specification"
+ */
+ if ((c->x86_vendor == X86_VENDOR_INTEL) && !(reg->access_size & 0x2))
+ cx->bm_sts_skip = 1;
+
return retval;
}
EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe);