PM: Drop pm_flags that is not necessary

The variable pm_flags is used to prevent APM from being enabled along with ACPI, which would lead to problems. However, acpi_init() is always called before apm_init() and after acpi_init() has returned, it is known whether or not ACPI will be used. Namely, if acpi_disabled is not set after acpi_init() has returned, this means that ACPI is enabled. Thus, it is sufficient to check acpi_disabled in apm_init() to prevent APM from being enabled in parallel with ACPI. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>

PM: Drop pm_flags that is not necessary
The variable pm_flags is used to prevent APM from being enabled along with ACPI, which would lead to problems. However, acpi_init() is always called before apm_init() and after acpi_init() has returned, it is known whether or not ACPI will be used. Namely, if acpi_disabled is not set after acpi_init() has returned, this means that ACPI is enabled. Thus, it is sufficient to check acpi_disabled in apm_init() to prevent APM from being enabled in parallel with ACPI. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>
Rafael J. Wysocki
1 parent e866500247
Showing 5 changed files with 7 additions and 48 deletions Side-by-side Diff
arch/x86/kernel/apm_32.c
drivers/acpi/bus.c
include/linux/pm.h
include/linux/suspend.h
kernel/power/main.c
@@ -227,6 +227,7 @@
 #include <linux/suspend.h>
 #include <linux/kthread.h>
 #include <linux/jiffies.h>
+#include <linux/acpi.h>
  
 #include <asm/system.h>
 #include <asm/uaccess.h>
  
@@ -2331,12 +2332,11 @@
 		apm_info.disabled = 1;
 		return -ENODEV;
 	}
-	if (pm_flags & PM_ACPI) {
+	if (!acpi_disabled) {
 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
 		apm_info.disabled = 1;
 		return -ENODEV;
 	}
-	pm_flags |= PM_APM;
  
 	/*
 	 * Set up the long jump entry point to the APM BIOS, which is called
@@ -2428,7 +2428,6 @@
 		kthread_stop(kapmd_task);
 		kapmd_task = NULL;
 	}
-	pm_flags &= ~PM_APM;
 }
  
 module_init(apm_init);
@@ -1007,9 +1007,8 @@
  
 static int __init acpi_init(void)
 {
-	int result = 0;
+	int result;
  
-
 	if (acpi_disabled) {
 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
 		return -ENODEV;
  
  
  
  
@@ -1023,29 +1022,18 @@
  
 	init_acpi_device_notify();
 	result = acpi_bus_init();
-
-	if (!result) {
-		pci_mmcfg_late_init();
-		if (pm_apm_enabled()) {
-			printk(KERN_INFO PREFIX
-			       "APM is already active, exiting\n");
-			disable_acpi();
-			result = -ENODEV;
-		} else {
-			pm_set_acpi_flag();
-		}
-	} else
+	if (result) {
 		disable_acpi();
-
-	if (acpi_disabled)
 		return result;
+	}
  
+	pci_mmcfg_late_init();
 	acpi_scan_init();
 	acpi_ec_init();
 	acpi_debugfs_init();
 	acpi_sleep_proc_init();
 	acpi_wakeup_device_init();
-	return result;
+	return 0;
 }
  
 subsys_initcall(acpi_init);
@@ -565,15 +565,6 @@
 	DPM_ORDER_DEV_LAST,
 };
  
-/*
- * Global Power Management flags
- * Used to keep APM and ACPI from both being active
- */
-extern unsigned int	pm_flags;
-
-#define PM_APM	1
-#define PM_ACPI	2
-
 extern int pm_generic_suspend(struct device *dev);
 extern int pm_generic_resume(struct device *dev);
 extern int pm_generic_freeze(struct device *dev);
@@ -272,9 +272,6 @@
 	register_pm_notifier(&fn##_nb);			\
 }
  
-extern bool pm_apm_enabled(void);
-extern void pm_set_acpi_flag(void);
-
 /* drivers/base/power/wakeup.c */
 extern bool events_check_enabled;
  
@@ -294,9 +291,6 @@
 }
  
 #define pm_notifier(fn, pri)	do { (void)(fn); } while (0)
-
-static inline bool pm_apm_enabled(void) { return false; }
-static inline void pm_set_acpi_flag(void) {}
  
 static inline bool pm_wakeup_pending(void) { return false; }
 #endif /* !CONFIG_PM_SLEEP */
@@ -19,19 +19,6 @@
  
 #ifdef CONFIG_PM_SLEEP
  
-unsigned int pm_flags;
-EXPORT_SYMBOL(pm_flags);
-
-bool pm_apm_enabled(void)
-{
-	return !!(pm_flags & PM_APM);
-}
-
-void pm_set_acpi_flag(void)
-{
-	pm_flags |= PM_ACPI;
-}
-
 /* Routines for PM-transition notifications */
  
 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
...	...	@@ -227,6 +227,7 @@
227	227	#include <linux/suspend.h>
228	228	#include <linux/kthread.h>
229	229	#include <linux/jiffies.h>
	230	+#include <linux/acpi.h>
230	231
231	232	#include <asm/system.h>
232	233	#include <asm/uaccess.h>
233	234
...	...	@@ -2331,12 +2332,11 @@
2331	2332	apm_info.disabled = 1;
2332	2333	return -ENODEV;
2333	2334	}
2334		- if (pm_flags & PM_ACPI) {
	2335	+ if (!acpi_disabled) {
2335	2336	printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2336	2337	apm_info.disabled = 1;
2337	2338	return -ENODEV;
2338	2339	}
2339		- pm_flags \|= PM_APM;
2340	2340
2341	2341	/*
2342	2342	* Set up the long jump entry point to the APM BIOS, which is called
...	...	@@ -2428,7 +2428,6 @@
2428	2428	kthread_stop(kapmd_task);
2429	2429	kapmd_task = NULL;
2430	2430	}
2431		- pm_flags &= ~PM_APM;
2432	2431	}
2433	2432
2434	2433	module_init(apm_init);
...	...	@@ -1007,9 +1007,8 @@
1007	1007
1008	1008	static int __init acpi_init(void)
1009	1009	{
1010		- int result = 0;
	1010	+ int result;
1011	1011
1012		-
1013	1012	if (acpi_disabled) {
1014	1013	printk(KERN_INFO PREFIX "Interpreter disabled.\n");
1015	1014	return -ENODEV;
1016	1015
1017	1016
1018	1017
1019	1018
...	...	@@ -1023,29 +1022,18 @@
1023	1022
1024	1023	init_acpi_device_notify();
1025	1024	result = acpi_bus_init();
1026		-
1027		- if (!result) {
1028		- pci_mmcfg_late_init();
1029		- if (pm_apm_enabled()) {
1030		- printk(KERN_INFO PREFIX
1031		- "APM is already active, exiting\n");
1032		- disable_acpi();
1033		- result = -ENODEV;
1034		- } else {
1035		- pm_set_acpi_flag();
1036		- }
1037		- } else
	1025	+ if (result) {
1038	1026	disable_acpi();
1039		-
1040		- if (acpi_disabled)
1041	1027	return result;
	1028	+ }
1042	1029
	1030	+ pci_mmcfg_late_init();
1043	1031	acpi_scan_init();
1044	1032	acpi_ec_init();
1045	1033	acpi_debugfs_init();
1046	1034	acpi_sleep_proc_init();
1047	1035	acpi_wakeup_device_init();
1048		- return result;
	1036	+ return 0;
1049	1037	}
1050	1038
1051	1039	subsys_initcall(acpi_init);
...	...	@@ -565,15 +565,6 @@
565	565	DPM_ORDER_DEV_LAST,
566	566	};
567	567
568		-/*
569		- * Global Power Management flags
570		- * Used to keep APM and ACPI from both being active
571		- */
572		-extern unsigned int pm_flags;
573		-
574		-#define PM_APM 1
575		-#define PM_ACPI 2
576		-
577	568	extern int pm_generic_suspend(struct device *dev);
578	569	extern int pm_generic_resume(struct device *dev);
579	570	extern int pm_generic_freeze(struct device *dev);
...	...	@@ -272,9 +272,6 @@
272	272	register_pm_notifier(&fn##_nb); \
273	273	}
274	274
275		-extern bool pm_apm_enabled(void);
276		-extern void pm_set_acpi_flag(void);
277		-
278	275	/* drivers/base/power/wakeup.c */
279	276	extern bool events_check_enabled;
280	277
...	...	@@ -294,9 +291,6 @@
294	291	}
295	292
296	293	#define pm_notifier(fn, pri) do { (void)(fn); } while (0)
297		-
298		-static inline bool pm_apm_enabled(void) { return false; }
299		-static inline void pm_set_acpi_flag(void) {}
300	294
301	295	static inline bool pm_wakeup_pending(void) { return false; }
302	296	#endif /* !CONFIG_PM_SLEEP */
...	...	@@ -19,19 +19,6 @@
19	19
20	20	#ifdef CONFIG_PM_SLEEP
21	21
22		-unsigned int pm_flags;
23		-EXPORT_SYMBOL(pm_flags);
24		-
25		-bool pm_apm_enabled(void)
26		-{
27		- return !!(pm_flags & PM_APM);
28		-}
29		-
30		-void pm_set_acpi_flag(void)
31		-{
32		- pm_flags \|= PM_ACPI;
33		-}
34		-
35	22	/* Routines for PM-transition notifications */
36	23
37	24	static BLOCKING_NOTIFIER_HEAD(pm_chain_head);