GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-22 23:04:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

rework pm_ops pm_disk_mode, kill misuse

Browse source 
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>
This commit is contained in:
Johannes Berg 2007-04-30 15:09:51 -07:00 • committed by Linus Torvalds
parent 1173a729fc
commit fe0c935a6c
11 changed files with 56 additions and 64 deletions
Download patch file Download diff file Expand all files Collapse all files

6
kernel/power/main.c
View file

@ -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);
}