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path: root/drivers/acpi/processor_perflib.c
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Diffstat (limited to 'drivers/acpi/processor_perflib.c')
-rw-r--r--drivers/acpi/processor_perflib.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 836bfe069042..53e7ac9403a7 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -340,6 +340,13 @@ static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
|| boot_cpu_data.x86 == 0x11) {
rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
+ /*
+ * MSR C001_0064+:
+ * Bit 63: PstateEn. Read-write. If set, the P-state is valid.
+ */
+ if (!(hi & BIT(31)))
+ return;
+
fid = lo & 0x3f;
did = (lo >> 6) & 7;
if (boot_cpu_data.x86 == 0x10)