On Tue, 2017-02-28 at 00:05 +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>
> 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 <rafael.j.wyso...@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com>
> ---
> 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();
>
