Need to replace one patch in suspend branch

Need to replace one patch in suspend branch

[Rafael J. Wysocki]

Hi Len,

Would it be possible to replace commit a04ca6718960e842624833a01dbd5f10f38f5af1
"Suspend: Testing facility (rev. 2)" in the suspend branch with the appended patch?

Unfortunately, the original commit uses pointers to 'struct kset' which is no
longer valid after the recently merged driver core changes.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rjw@sisk.pl>

Introduce sysfs attribute /sys/power/pm_test allowing one to test the suspend
core code.  Namely, writing one of the strings:

freezer
devices
platform
processors
core

to this file causes the suspend code to work in one of the test modes defined as
follows:

freezer
- test the freezing of processes

devices
- test the freezing of processes and suspending of devices

platform
- test the freezing of processes, suspending of devices and platform global
  control methods(*)

processors
- test the freezing of processes, suspending of devices, platform global
  control methods and the disabling of nonboot CPUs

core
- test the freezing of processes, suspending of devices, platform global
  control methods, the disabling of nonboot CPUs and suspending of
  platform/system devices

(*) These are ACPI global control methods on ACPI systems

Then, if a suspend is started by normal means, the suspend core will perform
its normal operations up to the point indicated by given test level.  Next, it
will wait for 5 seconds and carry out the resume operations needed to transition
the system back to the fully functional state.

Writing "none" to /sys/power/pm_test turns the testing off.

When open for reading, /sys/power/pm_test contains a space-separated list of all
available tests (including "none" that represents the normal functionality) in
which the current test level is indicated by square brackets.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 kernel/power/main.c  |  111 ++++++++++++++++++++++++++++++++++++++++++++++-----
 kernel/power/power.h |   18 ++++++++
 2 files changed, 120 insertions(+), 9 deletions(-)

Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -31,6 +31,82 @@ DEFINE_MUTEX(pm_mutex);
 unsigned int pm_flags;
 EXPORT_SYMBOL(pm_flags);
 
+#ifdef CONFIG_PM_DEBUG
+int pm_test_level = TEST_NONE;
+
+static int suspend_test(int level)
+{
+	if (pm_test_level == level) {
+		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
+		mdelay(5000);
+		return 1;
+	}
+	return 0;
+}
+
+static const char * const pm_tests[__TEST_AFTER_LAST] = {
+	[TEST_NONE] = "none",
+	[TEST_CORE] = "core",
+	[TEST_CPUS] = "processors",
+	[TEST_PLATFORM] = "platform",
+	[TEST_DEVICES] = "devices",
+	[TEST_FREEZER] = "freezer",
+};
+
+static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
+				char *buf)
+{
+	char *s = buf;
+	int level;
+
+	for (level = TEST_FIRST; level <= TEST_MAX; level++)
+		if (pm_tests[level]) {
+			if (level == pm_test_level)
+				s += sprintf(s, "[%s] ", pm_tests[level]);
+			else
+				s += sprintf(s, "%s ", pm_tests[level]);
+		}
+
+	if (s != buf)
+		/* convert the last space to a newline */
+		*(s-1) = '\n';
+
+	return (s - buf);
+}
+
+static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
+				const char *buf, size_t n)
+{
+	const char * const *s;
+	int level;
+	char *p;
+	int len;
+	int error = -EINVAL;
+
+	p = memchr(buf, '\n', n);
+	len = p ? p - buf : n;
+
+	mutex_lock(&pm_mutex);
+
+	level = TEST_FIRST;
+	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
+		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
+			pm_test_level = level;
+			error = 0;
+			break;
+		}
+
+	mutex_unlock(&pm_mutex);
+
+	return error ? error : n;
+}
+
+power_attr(pm_test);
+#else /* !CONFIG_PM_DEBUG */
+static inline int suspend_test(int level) { return 0; }
+#endif /* !CONFIG_PM_DEBUG */
+
+
 #ifdef CONFIG_SUSPEND
 
 /* This is just an arbitrary number */
@@ -136,7 +212,10 @@ static int suspend_enter(suspend_state_t
 		printk(KERN_ERR "Some devices failed to power down\n");
 		goto Done;
 	}
-	error = suspend_ops->enter(state);
+
+	if (!suspend_test(TEST_CORE))
+		error = suspend_ops->enter(state);
+
 	device_power_up();
  Done:
 	arch_suspend_enable_irqs();
@@ -167,16 +246,25 @@ int suspend_devices_and_enter(suspend_st
 		printk(KERN_ERR "Some devices failed to suspend\n");
 		goto Resume_console;
 	}
+
+	if (suspend_test(TEST_DEVICES))
+		goto Resume_devices;
+
 	if (suspend_ops->prepare) {
 		error = suspend_ops->prepare();
 		if (error)
 			goto Resume_devices;
 	}
+
+	if (suspend_test(TEST_PLATFORM))
+		goto Finish;
+
 	error = disable_nonboot_cpus();
-	if (!error)
+	if (!error && !suspend_test(TEST_CPUS))
 		suspend_enter(state);
 
 	enable_nonboot_cpus();
+ Finish:
 	if (suspend_ops->finish)
 		suspend_ops->finish();
  Resume_devices:
@@ -243,12 +331,17 @@ static int enter_state(suspend_state_t s
 	printk("done.\n");
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-	if ((error = suspend_prepare()))
+	error = suspend_prepare();
+	if (error)
 		goto Unlock;
 
+	if (suspend_test(TEST_FREEZER))
+		goto Finish;
+
 	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
 	error = suspend_devices_and_enter(state);
 
+ Finish:
 	pr_debug("PM: Finishing wakeup.\n");
 	suspend_finish();
  Unlock:
@@ -369,18 +462,18 @@ pm_trace_store(struct kobject *kobj, str
 }
 
 power_attr(pm_trace);
+#endif /* CONFIG_PM_TRACE */
 
 static struct attribute * g[] = {
 	&state_attr.attr,
+#ifdef CONFIG_PM_TRACE
 	&pm_trace_attr.attr,
+#endif
+#ifdef CONFIG_PM_DEBUG
+	&pm_test_attr.attr,
+#endif
 	NULL,
 };
-#else
-static struct attribute * g[] = {
-	&state_attr.attr,
-	NULL,
-};
-#endif /* CONFIG_PM_TRACE */
 
 static struct attribute_group attr_group = {
 	.attrs = g,
Index: linux-2.6/kernel/power/power.h
===================================================================
--- linux-2.6.orig/kernel/power/power.h
+++ linux-2.6/kernel/power/power.h
@@ -188,3 +188,21 @@ int restore_highmem(void);
 static inline unsigned int count_highmem_pages(void) { return 0; }
 static inline int restore_highmem(void) { return 0; }
 #endif
+
+/*
+ * Suspend test levels
+ */
+enum {
+	/* keep first */
+	TEST_NONE,
+	TEST_CORE,
+	TEST_CPUS,
+	TEST_PLATFORM,
+	TEST_DEVICES,
+	TEST_FREEZER,
+	/* keep last */
+	__TEST_AFTER_LAST
+};
+
+#define TEST_FIRST	TEST_NONE
+#define TEST_MAX	(__TEST_AFTER_LAST - 1)

Re: Need to replace one patch in suspend branch

[Len Brown]

On Monday 28 January 2008 18:29, Rafael J. Wysocki wrote:
> Hi Len,
> 
> Would it be possible to replace commit a04ca6718960e842624833a01dbd5f10f38f5af1
> "Suspend: Testing facility (rev. 2)" in the suspend branch with the appended patch?
> 
> Unfortunately, the original commit uses pointers to 'struct kset' which is no
> longer valid after the recently merged driver core changes.

Hi Rafael,
The original suspend branch is now available rooted at 2.6.24
as "suspend-2.6.24".

The latest "suspend" branch is now based on today's linus HEAD.

In the suspend branch, I rewound the series until after the
original patch, patch -R the original, patch -N the new one,
and checked in the the resulting diff (below).

At the expense of the additional trivial patch,
this struck me as a good balance between preserving
the (tested) history, showing what changed,
and minimizing exposure to bisect build breakage.

thanks,
-Len

commit 21779c8de31b1c9e749af676a033109f70156678
Author: Rafael J. Wysocki <rjw@sisk.pl>
Date:   Tue Jan 29 00:29:06 2008 +0100

    suspend: build fix responding to 2.6.25 kset change
    
    Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
    Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 84e1ae6..fc717b8 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -53,7 +53,8 @@ static const char * const pm_tests[__TEST_AFTER_LAST] = {
 	[TEST_FREEZER] = "freezer",
 };
 
-static ssize_t pm_test_show(struct kset *kset, char *buf)
+static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
+				char *buf)
 {
 	char *s = buf;
 	int level;
@@ -73,7 +74,8 @@ static ssize_t pm_test_show(struct kset *kset, char *buf)
 	return (s - buf);
 }
 
-static ssize_t pm_test_store(struct kset *kset, const char *buf, size_t n)
+static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
+				const char *buf, size_t n)
 {
 	const char * const *s;
 	int level;
@@ -104,6 +106,7 @@ power_attr(pm_test);
 static inline int suspend_test(int level) { return 0; }
 #endif /* !CONFIG_PM_DEBUG */
 
+
 #ifdef CONFIG_SUSPEND
 
 /* This is just an arbitrary number */

Re: Need to replace one patch in suspend branch

[Rafael J. Wysocki]

On Friday, 1 of February 2008, Len Brown wrote:
> On Monday 28 January 2008 18:29, Rafael J. Wysocki wrote:
> > Hi Len,
> > 
> > Would it be possible to replace commit a04ca6718960e842624833a01dbd5f10f38f5af1
> > "Suspend: Testing facility (rev. 2)" in the suspend branch with the appended patch?
> > 
> > Unfortunately, the original commit uses pointers to 'struct kset' which is no
> > longer valid after the recently merged driver core changes.
> 
> Hi Rafael,
> The original suspend branch is now available rooted at 2.6.24
> as "suspend-2.6.24".
> 
> The latest "suspend" branch is now based on today's linus HEAD.

Thanks a lot for doing that!

> In the suspend branch, I rewound the series until after the
> original patch, patch -R the original, patch -N the new one,
> and checked in the the resulting diff (below).
> 
> At the expense of the additional trivial patch,
> this struck me as a good balance between preserving
> the (tested) history, showing what changed,
> and minimizing exposure to bisect build breakage.

Yes, this is a good idea to add this additional patch after the original one.

Thanks,
Rafael


> commit 21779c8de31b1c9e749af676a033109f70156678
> Author: Rafael J. Wysocki <rjw@sisk.pl>
> Date:   Tue Jan 29 00:29:06 2008 +0100
> 
>     suspend: build fix responding to 2.6.25 kset change
>     
>     Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
>     Signed-off-by: Len Brown <len.brown@intel.com>
> 
> diff --git a/kernel/power/main.c b/kernel/power/main.c
> index 84e1ae6..fc717b8 100644
> --- a/kernel/power/main.c
> +++ b/kernel/power/main.c
> @@ -53,7 +53,8 @@ static const char * const pm_tests[__TEST_AFTER_LAST] = {
>  	[TEST_FREEZER] = "freezer",
>  };
>  
> -static ssize_t pm_test_show(struct kset *kset, char *buf)
> +static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
> +				char *buf)
>  {
>  	char *s = buf;
>  	int level;
> @@ -73,7 +74,8 @@ static ssize_t pm_test_show(struct kset *kset, char *buf)
>  	return (s - buf);
>  }
>  
> -static ssize_t pm_test_store(struct kset *kset, const char *buf, size_t n)
> +static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
> +				const char *buf, size_t n)
>  {
>  	const char * const *s;
>  	int level;
> @@ -104,6 +106,7 @@ power_attr(pm_test);
>  static inline int suspend_test(int level) { return 0; }
>  #endif /* !CONFIG_PM_DEBUG */
>  
> +
>  #ifdef CONFIG_SUSPEND
>  
>  /* This is just an arbitrary number */
> 
>