From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: Re: [PATCH] cpufreq: intel_pstate: Fix operation mode switching Date: Mon, 27 Feb 2017 18:11:47 -0800 Message-ID: <1488247907.4085.0.camel@linux.intel.com> References: <2958124.3ADodeN5Y5@aspire.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mga05.intel.com ([192.55.52.43]:15954 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbdB1CPE (ORCPT ); Mon, 27 Feb 2017 21:15:04 -0500 In-Reply-To: <2958124.3ADodeN5Y5@aspire.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" , Linux PM Cc: LKML On Tue, 2017-02-28 at 00:05 +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > There is a problem with intel_pstate operation mode switching > introduced by commit fb1fe1041c04 (cpufreq: intel_pstate: Operation > mode control from sysfs), because the global sysfs limits are > preserved across operation modes while per-policy limits are > reinitialized from scratch and both sets of limits may get out of > sync this wya. > > Fix that by always reinitializing the global limits upon the > registration of the driver. > > Fixes: fb1fe1041c04 (cpufreq: intel_pstate: Operation mode control > from sysfs) > Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada > --- >  drivers/cpufreq/intel_pstate.c |   65 +++++++++++++----------------- > ----------- >  1 file changed, 22 insertions(+), 43 deletions(-) > > Index: linux-pm/drivers/cpufreq/intel_pstate.c > =================================================================== > --- linux-pm.orig/drivers/cpufreq/intel_pstate.c > +++ linux-pm/drivers/cpufreq/intel_pstate.c > @@ -364,37 +364,25 @@ static bool driver_registered __read_mos >  static bool acpi_ppc; >  #endif >   > -static struct perf_limits performance_limits = { > - .no_turbo = 0, > - .turbo_disabled = 0, > - .max_perf_pct = 100, > - .max_perf = int_ext_tofp(1), > - .min_perf_pct = 100, > - .min_perf = int_ext_tofp(1), > - .max_policy_pct = 100, > - .max_sysfs_pct = 100, > - .min_policy_pct = 0, > - .min_sysfs_pct = 0, > -}; > +static struct perf_limits performance_limits; > +static struct perf_limits powersave_limits; > +static struct perf_limits *limits; >   > -static struct perf_limits powersave_limits = { > - .no_turbo = 0, > - .turbo_disabled = 0, > - .max_perf_pct = 100, > - .max_perf = int_ext_tofp(1), > - .min_perf_pct = 0, > - .min_perf = 0, > - .max_policy_pct = 100, > - .max_sysfs_pct = 100, > - .min_policy_pct = 0, > - .min_sysfs_pct = 0, > -}; > +static void intel_pstate_init_limits(struct perf_limits *limits) > +{ > + memset(limits, 0, sizeof(*limits)); > + limits->max_perf_pct = 100; > + limits->max_perf = int_ext_tofp(1); > + limits->max_policy_pct = 100; > + limits->max_sysfs_pct = 100; > +} >   > -#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE > -static struct perf_limits *limits = &performance_limits; > -#else > -static struct perf_limits *limits = &powersave_limits; > -#endif > +static void intel_pstate_set_performance_limits(struct perf_limits > *limits) > +{ > + intel_pstate_init_limits(limits); > + limits->min_perf_pct = 100; > + limits->min_perf = int_ext_tofp(1); > +} >   >  static DEFINE_MUTEX(intel_pstate_driver_lock); >  static DEFINE_MUTEX(intel_pstate_limits_lock); > @@ -2084,20 +2072,6 @@ static void intel_pstate_clear_update_ut >   synchronize_sched(); >  } >   > -static void intel_pstate_set_performance_limits(struct perf_limits > *limits) > -{ > - limits->no_turbo = 0; > - limits->turbo_disabled = 0; > - limits->max_perf_pct = 100; > - limits->max_perf = int_ext_tofp(1); > - limits->min_perf_pct = 100; > - limits->min_perf = int_ext_tofp(1); > - limits->max_policy_pct = 100; > - limits->max_sysfs_pct = 100; > - limits->min_policy_pct = 0; > - limits->min_sysfs_pct = 0; > -} > - >  static void intel_pstate_update_perf_limits(struct cpufreq_policy > *policy, >       struct perf_limits > *limits) >  { > @@ -2466,6 +2440,11 @@ static int intel_pstate_register_driver( >  { >   int ret; >   > + intel_pstate_init_limits(&powersave_limits); > + intel_pstate_set_performance_limits(&performance_limits); > + limits = IS_ENABLED(CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE) > ? > + &performance_limits : &powersave_limits; > + >   ret = cpufreq_register_driver(intel_pstate_driver); >   if (ret) { >   intel_pstate_driver_cleanup(); >