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authorJohannes Berg <johannes@sipsolutions.net>2007-04-30 15:09:51 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-30 16:40:40 -0700
commitfe0c935a6cbf25d72a27c7a345df8a2151de0b74 (patch)
tree841a847412694ee586b0ca7e1e2ce7c45700d9b1 /kernel
parent1173a729fc3ce2fa0d698bd39be8ff7bf6c70bf1 (diff)
downloadlinux-linaro-stable-fe0c935a6cbf25d72a27c7a345df8a2151de0b74.tar.gz
rework pm_ops pm_disk_mode, kill misuse
This patch series cleans up some misconceptions about pm_ops. Some users of the pm_ops structure attempt to use it to stop the user from entering suspend to disk, this, however, is not possible since the user can always use "shutdown" in /sys/power/disk and then the pm_ops are never invoked. Also, platforms that don't support suspend to disk simply should not allow configuring SOFTWARE_SUSPEND (read the help text on it, it only selects suspend to disk and nothing else, all the other stuff depends on PM). The pm_ops structure is actually intended to provide a way to enter platform-defined sleep states (currently supported states are "standby" and "mem" (suspend to ram)) and additionally (if SOFTWARE_SUSPEND is configured) allows a platform to support a platform specific way to enter low-power mode once everything has been saved to disk. This is currently only used by ACPI (S4). This patch: The pm_ops.pm_disk_mode is used in totally bogus ways since nobody really seems to understand what it actually does. This patch clarifies the pm_disk_mode description. It also removes all the arm and sh users that think they can veto suspend to disk via pm_ops; not so since the user can always do echo shutdown > /sys/power/disk, they need to find a better way involving Kconfig or such. ACPI is the only user left with a non-zero pm_disk_mode. The patch also sets the default mode to shutdown again, but when a new pm_ops is registered its pm_disk_mode is selected as default, that way the default stays for ACPI where it is apparently required. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Cc: David Brownell <david-b@pacbell.net> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <linux-pm@lists.linux-foundation.org> Cc: Len Brown <lenb@kernel.org> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Greg KH <greg@kroah.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/disk.c60
-rw-r--r--kernel/power/main.c6
2 files changed, 44 insertions, 22 deletions
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index aec19b063e3f..4de2f69fe095 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -39,7 +39,13 @@ static inline int platform_prepare(void)
{
int error = 0;
- if (pm_disk_mode == PM_DISK_PLATFORM) {
+ switch (pm_disk_mode) {
+ case PM_DISK_TEST:
+ case PM_DISK_TESTPROC:
+ case PM_DISK_SHUTDOWN:
+ case PM_DISK_REBOOT:
+ break;
+ default:
if (pm_ops && pm_ops->prepare)
error = pm_ops->prepare(PM_SUSPEND_DISK);
}
@@ -48,40 +54,48 @@ static inline int platform_prepare(void)
/**
* power_down - Shut machine down for hibernate.
- * @mode: Suspend-to-disk mode
*
- * Use the platform driver, if configured so, and return gracefully if it
- * fails.
- * Otherwise, try to power off and reboot. If they fail, halt the machine,
- * there ain't no turning back.
+ * Use the platform driver, if configured so; otherwise try
+ * to power off or reboot.
*/
-static void power_down(suspend_disk_method_t mode)
+static void power_down(void)
{
- switch(mode) {
- case PM_DISK_PLATFORM:
- if (pm_ops && pm_ops->enter) {
- kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
- pm_ops->enter(PM_SUSPEND_DISK);
- break;
- }
+ switch (pm_disk_mode) {
+ case PM_DISK_TEST:
+ case PM_DISK_TESTPROC:
+ break;
case PM_DISK_SHUTDOWN:
kernel_power_off();
break;
case PM_DISK_REBOOT:
kernel_restart(NULL);
break;
+ default:
+ if (pm_ops && pm_ops->enter) {
+ kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
+ pm_ops->enter(PM_SUSPEND_DISK);
+ break;
+ }
}
kernel_halt();
- /* Valid image is on the disk, if we continue we risk serious data corruption
- after resume. */
+ /*
+ * Valid image is on the disk, if we continue we risk serious data
+ * corruption after resume.
+ */
printk(KERN_CRIT "Please power me down manually\n");
while(1);
}
static inline void platform_finish(void)
{
- if (pm_disk_mode == PM_DISK_PLATFORM) {
+ switch (pm_disk_mode) {
+ case PM_DISK_TEST:
+ case PM_DISK_TESTPROC:
+ case PM_DISK_SHUTDOWN:
+ case PM_DISK_REBOOT:
+ break;
+ default:
if (pm_ops && pm_ops->finish)
pm_ops->finish(PM_SUSPEND_DISK);
}
@@ -166,7 +180,7 @@ int pm_suspend_disk(void)
pr_debug("PM: writing image.\n");
error = swsusp_write();
if (!error)
- power_down(pm_disk_mode);
+ power_down();
else {
swsusp_free();
goto Thaw;
@@ -338,10 +352,14 @@ static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
}
}
if (mode) {
- if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
- mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
+ switch (mode) {
+ case PM_DISK_SHUTDOWN:
+ case PM_DISK_REBOOT:
+ case PM_DISK_TEST:
+ case PM_DISK_TESTPROC:
pm_disk_mode = mode;
- } else {
+ break;
+ default:
if (pm_ops && pm_ops->enter &&
(mode == pm_ops->pm_disk_mode))
pm_disk_mode = mode;
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3062e940d1fa..053c0a7d7f57 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -30,7 +30,7 @@
DEFINE_MUTEX(pm_mutex);
struct pm_ops *pm_ops;
-suspend_disk_method_t pm_disk_mode = PM_DISK_PLATFORM;
+suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
/**
* pm_set_ops - Set the global power method table.
@@ -41,6 +41,10 @@ void pm_set_ops(struct pm_ops * ops)
{
mutex_lock(&pm_mutex);
pm_ops = ops;
+ if (ops && ops->pm_disk_mode != PM_DISK_INVALID) {
+ pm_disk_mode = ops->pm_disk_mode;
+ } else
+ pm_disk_mode = PM_DISK_SHUTDOWN;
mutex_unlock(&pm_mutex);
}