From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Chen Yu , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH AUTOSEL for 4.15 166/189] cpufreq: intel_pstate: Enable HWP during system resume on CPU0 Date: Mon, 9 Apr 2018 00:19:00 +0000 Message-ID: <20180409001637.162453-166-alexander.levin@microsoft.com> References: <20180409001637.162453-1-alexander.levin@microsoft.com> In-Reply-To: <20180409001637.162453-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Chen Yu [ Upstream commit 70f6bf2a3b7e40c3f802b0ea837762a8bc6c1430 ] When maxcpus=3D1 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 Suggested-by: Srinivas Pandruvada Signed-off-by: Yu Chen [ rjw: Subject/changelog, minor modifications ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- 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_p= olicy *policy) return 0; } =20 +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 *p= olicy) =20 mutex_lock(&intel_pstate_limits_lock); =20 + if (policy->cpu =3D=3D 0) + intel_pstate_hwp_enable(all_cpu_data[policy->cpu]); + all_cpu_data[policy->cpu]->epp_policy =3D 0; intel_pstate_hwp_set(policy->cpu); =20 --=20 2.15.1