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-rw-r--r--drivers/acpi/cppc_acpi.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 1b207fca1420..d4244e7d0e38 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1150,8 +1150,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
cpc_read(cpunum, nominal_reg, &nom);
perf_caps->nominal_perf = nom;
- cpc_read(cpunum, guaranteed_reg, &guaranteed);
- perf_caps->guaranteed_perf = guaranteed;
+ if (guaranteed_reg->type != ACPI_TYPE_BUFFER ||
+ IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) {
+ perf_caps->guaranteed_perf = 0;
+ } else {
+ cpc_read(cpunum, guaranteed_reg, &guaranteed);
+ perf_caps->guaranteed_perf = guaranteed;
+ }
cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear);
perf_caps->lowest_nonlinear_perf = min_nonlinear;