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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2019-10-31 12:26:20 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-11-08 11:29:58 +0100
commitc31432fa7f825de0e19838f1ac7746381c509ec4 (patch)
treed5f4e09003c27b0a4a7342b55d64af786570926f /drivers/cpufreq
parenta99d8080aaf358d5d23581244e5da23b35e340b9 (diff)
cpufreq: intel_pstate: Fix invalid EPB setting
The max value of EPB can only be 0x0F. Attempting to set more than that triggers an "unchecked MSR access error" warning which happens in intel_pstate_hwp_force_min_perf() called via cpufreq stop_cpu(). However, it is not even necessary to touch the EPB from intel_pstate, because it is restored on every CPU online by the intel_epb.c code, so let that code do the right thing and drop the redundant (and incorrect) EPB update from intel_pstate. Fixes: af3b7379e2d70 ("cpufreq: intel_pstate: Force HWP min perf before offline") Reported-by: Qian Cai <cai@lca.pw> Cc: 5.2+ <stable@vger.kernel.org> # 5.2+ Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/intel_pstate.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 53a51c169451..8ab31702cf6a 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -847,11 +847,9 @@ static void intel_pstate_hwp_force_min_perf(int cpu)
value |= HWP_MAX_PERF(min_perf);
value |= HWP_MIN_PERF(min_perf);
- /* Set EPP/EPB to min */
+ /* Set EPP to min */
if (boot_cpu_has(X86_FEATURE_HWP_EPP))
value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE);
- else
- intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE);
wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
}