From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> The driver_registered variable in intel_pstate is used for checking whether or not the driver has been registered, but intel_pstate_driver can be used for that too (with the rule that the driver is not registered as long as it is NULL).
That is a bit more straightforward and the code may be simplified a bit this way, so modify the driver accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> --- drivers/cpufreq/intel_pstate.c | 46 ++++++++++++++++------------------------- 1 file changed, 19 insertions(+), 27 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -370,7 +370,7 @@ static struct pstate_adjust_policy pid_p static int hwp_active __read_mostly; static bool per_cpu_limits __read_mostly; -static bool driver_registered __read_mostly; +static struct cpufreq_driver *intel_pstate_driver __read_mostly; #ifdef CONFIG_ACPI static bool acpi_ppc; @@ -1083,7 +1083,7 @@ static ssize_t show_turbo_pct(struct kob mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -1108,7 +1108,7 @@ static ssize_t show_num_pstates(struct k mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -1128,7 +1128,7 @@ static ssize_t show_no_turbo(struct kobj mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -1156,7 +1156,7 @@ static ssize_t store_no_turbo(struct kob mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -1194,7 +1194,7 @@ static ssize_t store_max_perf_pct(struct mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -1231,7 +1231,7 @@ static ssize_t store_min_perf_pct(struct mutex_lock(&intel_pstate_driver_lock); - if (!driver_registered) { + if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } @@ -2346,7 +2346,7 @@ static struct cpufreq_driver intel_cpufr .name = "intel_cpufreq", }; -static struct cpufreq_driver *intel_pstate_driver = &intel_pstate; +static struct cpufreq_driver *default_driver = &intel_pstate; static void intel_pstate_driver_cleanup(void) { @@ -2363,12 +2363,14 @@ static void intel_pstate_driver_cleanup( } } put_online_cpus(); + intel_pstate_driver = NULL; } -static int intel_pstate_register_driver(void) +static int intel_pstate_register_driver(struct cpufreq_driver *driver) { int ret; + intel_pstate_driver = driver; intel_pstate_init_limits(&powersave_limits); intel_pstate_set_performance_limits(&performance_limits); if (IS_ENABLED(CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE) && @@ -2383,10 +2385,6 @@ static int intel_pstate_register_driver( return ret; } - mutex_lock(&intel_pstate_limits_lock); - driver_registered = true; - mutex_unlock(&intel_pstate_limits_lock); - if (intel_pstate_driver == &intel_pstate && !hwp_active && pstate_funcs.get_target_pstate != get_target_pstate_use_cpu_load) intel_pstate_debug_expose_params(); @@ -2403,10 +2401,6 @@ static int intel_pstate_unregister_drive pstate_funcs.get_target_pstate != get_target_pstate_use_cpu_load) intel_pstate_debug_hide_params(); - mutex_lock(&intel_pstate_limits_lock); - driver_registered = false; - mutex_unlock(&intel_pstate_limits_lock); - cpufreq_unregister_driver(intel_pstate_driver); intel_pstate_driver_cleanup(); @@ -2415,7 +2409,7 @@ static int intel_pstate_unregister_drive static ssize_t intel_pstate_show_status(char *buf) { - if (!driver_registered) + if (!intel_pstate_driver) return sprintf(buf, "off\n"); return sprintf(buf, "%s\n", intel_pstate_driver == &intel_pstate ? @@ -2427,11 +2421,11 @@ static int intel_pstate_update_status(co int ret; if (size == 3 && !strncmp(buf, "off", size)) - return driver_registered ? + return intel_pstate_driver ? intel_pstate_unregister_driver() : -EINVAL; if (size == 6 && !strncmp(buf, "active", size)) { - if (driver_registered) { + if (intel_pstate_driver) { if (intel_pstate_driver == &intel_pstate) return 0; @@ -2440,12 +2434,11 @@ static int intel_pstate_update_status(co return ret; } - intel_pstate_driver = &intel_pstate; - return intel_pstate_register_driver(); + return intel_pstate_register_driver(&intel_pstate); } if (size == 7 && !strncmp(buf, "passive", size)) { - if (driver_registered) { + if (intel_pstate_driver) { if (intel_pstate_driver != &intel_pstate) return 0; @@ -2454,8 +2447,7 @@ static int intel_pstate_update_status(co return ret; } - intel_pstate_driver = &intel_cpufreq; - return intel_pstate_register_driver(); + return intel_pstate_register_driver(&intel_cpufreq); } return -EINVAL; @@ -2684,7 +2676,7 @@ hwp_cpu_matched: intel_pstate_sysfs_expose_params(); mutex_lock(&intel_pstate_driver_lock); - rc = intel_pstate_register_driver(); + rc = intel_pstate_register_driver(default_driver); mutex_unlock(&intel_pstate_driver_lock); if (rc) return rc; @@ -2705,7 +2697,7 @@ static int __init intel_pstate_setup(cha no_load = 1; } else if (!strcmp(str, "passive")) { pr_info("Passive mode enabled\n"); - intel_pstate_driver = &intel_cpufreq; + default_driver = &intel_cpufreq; no_hwp = 1; } if (!strcmp(str, "no_hwp")) {