ACPI / Sleep: Allow the NVS saving to be skipped during suspend to RAM

Commit 2a6b69765ad794389f2fc3e14a0afa1a995221c2 (ACPI: Store NVS state even when entering suspend to RAM) caused the ACPI suspend code save the NVS area during suspend and restore it during resume unconditionally, although it is known that some systems need to use acpi_sleep=s4_nonvs for hibernation to work. To allow the affected systems to avoid saving and restoring the NVS area during suspend to RAM and resume, introduce kernel command line option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its alias temporarily (add acpi_sleep=s4_nonvs to the feature removal file). Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 . Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-and-tested-by: tomas m <tmezzadra@gmail.com> Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / Sleep: Allow the NVS saving to be skipped during suspend to RAM
Commit 2a6b69765ad794389f2fc3e14a0afa1a995221c2 (ACPI: Store NVS state even when entering suspend to RAM) caused the ACPI suspend code save the NVS area during suspend and restore it during resume unconditionally, although it is known that some systems need to use acpi_sleep=s4_nonvs for hibernation to work. To allow the affected systems to avoid saving and restoring the NVS area during suspend to RAM and resume, introduce kernel command line option acpi_sleep=nonvs and make acpi_sleep=s4_nonvs work as its alias temporarily (add acpi_sleep=s4_nonvs to the feature removal file). Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16396 . Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-and-tested-by: tomas m <tmezzadra@gmail.com> Signed-off-by: Len Brown <len.brown@intel.com>
Rafael J. Wysocki · Len Brown
1 parent b37fa16e78
Showing 5 changed files with 34 additions and 23 deletions Side-by-side Diff
Documentation/feature-removal-schedule.txt
Documentation/kernel-parameters.txt
arch/x86/kernel/acpi/sleep.c
drivers/acpi/sleep.c
include/linux/acpi.h
@@ -646,4 +646,12 @@
 Who:	Stefan Richter <stefanr@s5r6.in-berlin.de>
  
 ----------------------------
+
+What:	The acpi_sleep=s4_nonvs command line option
+When:	2.6.37
+Files:	arch/x86/kernel/acpi/sleep.c
+Why:	superseded by acpi_sleep=nonvs
+Who:	Rafael J. Wysocki <rjw@sisk.pl>
+
+----------------------------
@@ -254,8 +254,8 @@
 			control method, with respect to putting devices into
 			low power states, to be enforced (the ACPI 2.0 ordering
 			of _PTS is used by default).
-			s4_nonvs prevents the kernel from saving/restoring the
-			ACPI NVS memory during hibernation.
+			nonvs prevents the kernel from saving/restoring the
+			ACPI NVS memory during suspend/hibernation and resume.
 			sci_force_enable causes the kernel to set SCI_EN directly
 			on resume from S1/S3 (which is against the ACPI spec,
 			but some broken systems don't work without it).
@@ -157,9 +157,14 @@
 #ifdef CONFIG_HIBERNATION
 		if (strncmp(str, "s4_nohwsig", 10) == 0)
 			acpi_no_s4_hw_signature();
-		if (strncmp(str, "s4_nonvs", 8) == 0)
-			acpi_s4_no_nvs();
+		if (strncmp(str, "s4_nonvs", 8) == 0) {
+			pr_warning("ACPI: acpi_sleep=s4_nonvs is deprecated, "
+					"please use acpi_sleep=nonvs instead");
+			acpi_nvs_nosave();
+		}
 #endif
+		if (strncmp(str, "nonvs", 5) == 0)
+			acpi_nvs_nosave();
 		if (strncmp(str, "old_ordering", 12) == 0)
 			acpi_old_suspend_ordering();
 		str = strchr(str, ',');
@@ -82,6 +82,20 @@
 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
  
 /*
+ * The ACPI specification wants us to save NVS memory regions during hibernation
+ * and to restore them during the subsequent resume.  Windows does that also for
+ * suspend to RAM.  However, it is known that this mechanism does not work on
+ * all machines, so we allow the user to disable it with the help of the
+ * 'acpi_sleep=nonvs' kernel command line option.
+ */
+static bool nvs_nosave;
+
+void __init acpi_nvs_nosave(void)
+{
+	nvs_nosave = true;
+}
+
+/*
  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
  * user to request that behavior by using the 'acpi_old_suspend_ordering'
  * kernel command line option that causes the following variable to be set.
@@ -197,8 +211,7 @@
 	u32 acpi_state = acpi_suspend_states[pm_state];
 	int error = 0;
  
-	error = suspend_nvs_alloc();
-
+	error = nvs_nosave ? 0 : suspend_nvs_alloc();
 	if (error)
 		return error;
  
@@ -388,20 +401,6 @@
 #endif /* CONFIG_SUSPEND */
  
 #ifdef CONFIG_HIBERNATION
-/*
- * The ACPI specification wants us to save NVS memory regions during hibernation
- * and to restore them during the subsequent resume.  However, it is not certain
- * if this mechanism is going to work on all machines, so we allow the user to
- * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
- * option.
- */
-static bool s4_no_nvs;
-
-void __init acpi_s4_no_nvs(void)
-{
-	s4_no_nvs = true;
-}
-
 static unsigned long s4_hardware_signature;
 static struct acpi_table_facs *facs;
 static bool nosigcheck;
@@ -415,7 +414,7 @@
 {
 	int error;
  
-	error = s4_no_nvs ? 0 : suspend_nvs_alloc();
+	error = nvs_nosave ? 0 : suspend_nvs_alloc();
 	if (!error) {
 		acpi_target_sleep_state = ACPI_STATE_S4;
 		acpi_sleep_tts_switch(acpi_target_sleep_state);
@@ -510,7 +509,7 @@
 	error = acpi_sleep_prepare(ACPI_STATE_S4);
  
 	if (!error) {
-		if (!s4_no_nvs)
+		if (!nvs_nosave)
 			error = suspend_nvs_alloc();
 		if (!error)
 			acpi_target_sleep_state = ACPI_STATE_S4;
@@ -253,7 +253,7 @@
 #ifdef CONFIG_PM_SLEEP
 void __init acpi_no_s4_hw_signature(void);
 void __init acpi_old_suspend_ordering(void);
-void __init acpi_s4_no_nvs(void);
+void __init acpi_nvs_nosave(void);
 #endif /* CONFIG_PM_SLEEP */
  
 struct acpi_osc_context {
...	...	@@ -646,4 +646,12 @@
646	646	Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
647	647
648	648	----------------------------
	649	+
	650	+What: The acpi_sleep=s4_nonvs command line option
	651	+When: 2.6.37
	652	+Files: arch/x86/kernel/acpi/sleep.c
	653	+Why: superseded by acpi_sleep=nonvs
	654	+Who: Rafael J. Wysocki <rjw@sisk.pl>
	655	+
	656	+----------------------------
...	...	@@ -254,8 +254,8 @@
254	254	control method, with respect to putting devices into
255	255	low power states, to be enforced (the ACPI 2.0 ordering
256	256	of _PTS is used by default).
257		- s4_nonvs prevents the kernel from saving/restoring the
258		- ACPI NVS memory during hibernation.
	257	+ nonvs prevents the kernel from saving/restoring the
	258	+ ACPI NVS memory during suspend/hibernation and resume.
259	259	sci_force_enable causes the kernel to set SCI_EN directly
260	260	on resume from S1/S3 (which is against the ACPI spec,
261	261	but some broken systems don't work without it).
...	...	@@ -157,9 +157,14 @@
157	157	#ifdef CONFIG_HIBERNATION
158	158	if (strncmp(str, "s4_nohwsig", 10) == 0)
159	159	acpi_no_s4_hw_signature();
160		- if (strncmp(str, "s4_nonvs", 8) == 0)
161		- acpi_s4_no_nvs();
	160	+ if (strncmp(str, "s4_nonvs", 8) == 0) {
	161	+ pr_warning("ACPI: acpi_sleep=s4_nonvs is deprecated, "
	162	+ "please use acpi_sleep=nonvs instead");
	163	+ acpi_nvs_nosave();
	164	+ }
162	165	#endif
	166	+ if (strncmp(str, "nonvs", 5) == 0)
	167	+ acpi_nvs_nosave();
163	168	if (strncmp(str, "old_ordering", 12) == 0)
164	169	acpi_old_suspend_ordering();
165	170	str = strchr(str, ',');
...	...	@@ -82,6 +82,20 @@
82	82	static u32 acpi_target_sleep_state = ACPI_STATE_S0;
83	83
84	84	/*
	85	+ * The ACPI specification wants us to save NVS memory regions during hibernation
	86	+ * and to restore them during the subsequent resume. Windows does that also for
	87	+ * suspend to RAM. However, it is known that this mechanism does not work on
	88	+ * all machines, so we allow the user to disable it with the help of the
	89	+ * 'acpi_sleep=nonvs' kernel command line option.
	90	+ */
	91	+static bool nvs_nosave;
	92	+
	93	+void __init acpi_nvs_nosave(void)
	94	+{
	95	+ nvs_nosave = true;
	96	+}
	97	+
	98	+/*
85	99	* ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
86	100	* user to request that behavior by using the 'acpi_old_suspend_ordering'
87	101	* kernel command line option that causes the following variable to be set.
...	...	@@ -197,8 +211,7 @@
197	211	u32 acpi_state = acpi_suspend_states[pm_state];
198	212	int error = 0;
199	213
200		- error = suspend_nvs_alloc();
201		-
	214	+ error = nvs_nosave ? 0 : suspend_nvs_alloc();
202	215	if (error)
203	216	return error;
204	217
...	...	@@ -388,20 +401,6 @@
388	401	#endif /* CONFIG_SUSPEND */
389	402
390	403	#ifdef CONFIG_HIBERNATION
391		-/*
392		- * The ACPI specification wants us to save NVS memory regions during hibernation
393		- * and to restore them during the subsequent resume. However, it is not certain
394		- * if this mechanism is going to work on all machines, so we allow the user to
395		- * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
396		- * option.
397		- */
398		-static bool s4_no_nvs;
399		-
400		-void __init acpi_s4_no_nvs(void)
401		-{
402		- s4_no_nvs = true;
403		-}
404		-
405	404	static unsigned long s4_hardware_signature;
406	405	static struct acpi_table_facs *facs;
407	406	static bool nosigcheck;
...	...	@@ -415,7 +414,7 @@
415	414	{
416	415	int error;
417	416
418		- error = s4_no_nvs ? 0 : suspend_nvs_alloc();
	417	+ error = nvs_nosave ? 0 : suspend_nvs_alloc();
419	418	if (!error) {
420	419	acpi_target_sleep_state = ACPI_STATE_S4;
421	420	acpi_sleep_tts_switch(acpi_target_sleep_state);
...	...	@@ -510,7 +509,7 @@
510	509	error = acpi_sleep_prepare(ACPI_STATE_S4);
511	510
512	511	if (!error) {
513		- if (!s4_no_nvs)
	512	+ if (!nvs_nosave)
514	513	error = suspend_nvs_alloc();
515	514	if (!error)
516	515	acpi_target_sleep_state = ACPI_STATE_S4;
...	...	@@ -253,7 +253,7 @@
253	253	#ifdef CONFIG_PM_SLEEP
254	254	void __init acpi_no_s4_hw_signature(void);
255	255	void __init acpi_old_suspend_ordering(void);
256		-void __init acpi_s4_no_nvs(void);
	256	+void __init acpi_nvs_nosave(void);
257	257	#endif /* CONFIG_PM_SLEEP */
258	258
259	259	struct acpi_osc_context {