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>
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index aec19b0..4de2f69 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -39,7 +39,13 @@
{
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 @@
/**
* 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 @@
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 @@
}
}
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;