diff options
| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2019-10-31 12:26:20 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-11-08 11:29:58 +0100 |
| commit | c31432fa7f825de0e19838f1ac7746381c509ec4 (patch) | |
| tree | d5f4e09003c27b0a4a7342b55d64af786570926f /drivers/cpufreq/intel_pstate.c | |
| parent | a99d8080aaf358d5d23581244e5da23b35e340b9 (diff) | |
| download | linux-c31432fa7f825de0e19838f1ac7746381c509ec4.tar.bz2 | |
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/intel_pstate.c')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 4 |
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); } |