Merge tag 'pm-5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix reference counting in the operating performance points (OPP)
  framework and address a few intel_pstate driver issues, mostly related
  to switching driver operation modes and similar with hardware-managed
  P-states (HWP) enabled.

  Specifics:

   - Fix reference counting of operating performance points (OPP) tables
     (Viresh Kumar).

   - Address intel_pstate driver interface issues, mostly related to
     switching operation modes and handling CPU offline and online and
     system-wide suspend/resume with hardware-managed P-states (HWP)
     enabled (Rafael Wysocki).

   - Fix the maximum frequency computation in the intel_pstate driver
     with turbo P-states disabled by the platform firmware and HWP
     enabled (Francisco Jerez)"

* tag 'pm-5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Fix intel_pstate_get_hwp_max() for turbo disabled
  cpufreq: intel_pstate: Free memory only when turning off
  cpufreq: intel_pstate: Add ->offline and ->online callbacks
  cpufreq: intel_pstate: Tweak the EPP sysfs interface
  cpufreq: intel_pstate: Update cached EPP in the active mode
  cpufreq: intel_pstate: Refuse to turn off with HWP enabled
  opp: Don't drop reference for an OPP table that was never parsed

Documentation/admin-guide/pm/intel_pstate.rst

@@ -123,7 +123,9 @@ Energy-Performance Bias (EPB) knob (otherwise), which means that the processor's
 internal P-state selection logic is expected to focus entirely on performance.
 
 This will override the EPP/EPB setting coming from the ``sysfs`` interface
-(see `Energy vs Performance Hints`_ below).
+(see `Energy vs Performance Hints`_ below).  Moreover, any attempts to change
+the EPP/EPB to a value different from 0 ("performance") via ``sysfs`` in this
+configuration will be rejected.
 
 Also, in this configuration the range of P-states available to the processor's
 internal P-state selection logic is always restricted to the upper boundary

drivers/opp/core.c

@@ -1296,13 +1296,19 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 
-void _opp_remove_all_static(struct opp_table *opp_table)
+bool _opp_remove_all_static(struct opp_table *opp_table)
 {
 	struct dev_pm_opp *opp, *tmp;
+	bool ret = true;
 
 	mutex_lock(&opp_table->lock);
 
-	if (!opp_table->parsed_static_opps || --opp_table->parsed_static_opps)
+	if (!opp_table->parsed_static_opps) {
+		ret = false;
+		goto unlock;
+	}
+
+	if (--opp_table->parsed_static_opps)
 		goto unlock;
 
 	list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
@@ -1312,6 +1318,8 @@ void _opp_remove_all_static(struct opp_table *opp_table)
 
 unlock:
 	mutex_unlock(&opp_table->lock);
+
+	return ret;
 }
 
 /**
@@ -2414,12 +2422,14 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev)
 		return;
 	}
 
-	_opp_remove_all_static(opp_table);
-
-	/* Drop reference taken by _find_opp_table() */
+	/*
+	 * Drop the extra reference only if the OPP table was successfully added
+	 * with dev_pm_opp_of_add_table() earlier.
+	 **/
+	if (_opp_remove_all_static(opp_table))
 		dev_pm_opp_put_opp_table(opp_table);
 
-	/* Drop reference taken while the OPP table was added */
+	/* Drop reference taken by _find_opp_table() */
 	dev_pm_opp_put_opp_table(opp_table);
 }
 

drivers/opp/opp.h

@@ -212,7 +212,7 @@ struct opp_table {
 
 /* Routines internal to opp core */
 void dev_pm_opp_get(struct dev_pm_opp *opp);
-void _opp_remove_all_static(struct opp_table *opp_table);
+bool _opp_remove_all_static(struct opp_table *opp_table);
 void _get_opp_table_kref(struct opp_table *opp_table);
 int _get_opp_count(struct opp_table *opp_table);
 struct opp_table *_find_opp_table(struct device *dev);