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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2019-03-25 09:04:40 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-03-25 23:57:21 +0100
commit92a3e426ec06e72b1c363179c79d30712447ff76 (patch)
treef06ebdfb09105845f176608a015be1da5edea151
parentedef1ef134180149694b86386277076f566d165c (diff)
cpufreq: intel_pstate: Also use CPPC nominal_perf for base_frequency
The ACPI specification states that if the "Guaranteed Performance Register" is not implemented, the OSPM assumes guaranteed performance to always be equal to nominal performance. So for invalid or unimplemented guaranteed performance register, use nominal performance as guaranteed performance. This change will fall back to nominal_perf when guranteed_perf is invalid. If nominal_perf is also invalid or not present, fall back to the existing implementation, which is to read from HWP Capabilities MSR. Fixes: 86d333a8cc7f ("cpufreq: intel_pstate: Add base_frequency attribute") Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: 4.20+ <stable@vger.kernel.org> # 4.20+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/cpufreq/intel_pstate.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e22f0dbaebb1..b599c7318aab 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -385,7 +385,10 @@ static int intel_pstate_get_cppc_guranteed(int cpu)
if (ret)
return ret;
- return cppc_perf.guaranteed_perf;
+ if (cppc_perf.guaranteed_perf)
+ return cppc_perf.guaranteed_perf;
+
+ return cppc_perf.nominal_perf;
}
#else /* CONFIG_ACPI_CPPC_LIB */