From: Chen Yu <yu.c.c...@intel.com> [ Upstream commit 70f6bf2a3b7e40c3f802b0ea837762a8bc6c1430 ]
When maxcpus=1 is in the kernel command line, the BP is responsible for re-enabling the HWP - because currently only the APs invoke intel_pstate_hwp_enable() during their online process - which might put the system into unstable state after resume. Fix this by enabling the HWP explicitly on BP during resume. Reported-by: Doug Smythies <dsmyth...@telus.net> Suggested-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com> Signed-off-by: Yu Chen <yu.c.c...@intel.com> [ rjw: Subject/changelog, minor modifications ] Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Signed-off-by: Sasha Levin <alexander.le...@microsoft.com> --- drivers/cpufreq/intel_pstate.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 93a0e88bef76..20226d4243f2 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -779,6 +779,8 @@ static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy) return 0; } +static void intel_pstate_hwp_enable(struct cpudata *cpudata); + static int intel_pstate_resume(struct cpufreq_policy *policy) { if (!hwp_active) @@ -786,6 +788,9 @@ static int intel_pstate_resume(struct cpufreq_policy *policy) mutex_lock(&intel_pstate_limits_lock); + if (policy->cpu == 0) + intel_pstate_hwp_enable(all_cpu_data[policy->cpu]); + all_cpu_data[policy->cpu]->epp_policy = 0; intel_pstate_hwp_set(policy->cpu); -- 2.15.1