| Message ID | 7ddf56d88ed43701cd498fd42d1ae75e4eea1340.1517192577.git.yu.c.chen@intel.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
On Monday, January 29, 2018 3:27:57 AM CET Yu Chen wrote: > When maxcpus=1 is appended 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 <dsmythies@telus.net> > Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Signed-off-by: Yu Chen <yu.c.chen@intel.com> > --- > drivers/cpufreq/intel_pstate.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index 93a0e88bef76..89f637e8439c 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 +788,8 @@ static int intel_pstate_resume(struct cpufreq_policy *policy) > > mutex_lock(&intel_pstate_limits_lock); > > + if (!policy->cpu) > + intel_pstate_hwp_enable(all_cpu_data[policy->cpu]); > all_cpu_data[policy->cpu]->epp_policy = 0; > intel_pstate_hwp_set(policy->cpu); > > I've applied this one (with minor modifications) as a temporary measure, but it is based on the CPU0=BP assumption which may not be the case.
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 93a0e88bef76..89f637e8439c 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 +788,8 @@ static int intel_pstate_resume(struct cpufreq_policy *policy) mutex_lock(&intel_pstate_limits_lock); + if (!policy->cpu) + intel_pstate_hwp_enable(all_cpu_data[policy->cpu]); all_cpu_data[policy->cpu]->epp_policy = 0; intel_pstate_hwp_set(policy->cpu);
When maxcpus=1 is appended 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 <dsmythies@telus.net> Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Yu Chen <yu.c.chen@intel.com> --- drivers/cpufreq/intel_pstate.c | 4 ++++ 1 file changed, 4 insertions(+)