GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-21 06:01:23 +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

23
include/linux/pm.h
View file

@ -112,6 +112,8 @@ typedef int __bitwise suspend_state_t;
typedef int __bitwise suspend_disk_method_t;
/* invalid must be 0 so struct pm_ops initialisers can leave it out */
#define PM_DISK_INVALID ((__force suspend_disk_method_t) 0)
#define PM_DISK_FIRMWARE ((__force suspend_disk_method_t) 1)
#define PM_DISK_PLATFORM ((__force suspend_disk_method_t) 2)
#define PM_DISK_SHUTDOWN ((__force suspend_disk_method_t) 3)
@ -137,17 +139,16 @@ typedef int __bitwise suspend_disk_method_t;
* @finish: Called when the system has left the given state and all devices
* are resumed. The return value is ignored.
*
* @pm_disk_mode: Set to the disk method that the user should be able to
* configure for suspend-to-disk. Since %PM_DISK_SHUTDOWN,
* %PM_DISK_REBOOT, %PM_DISK_TEST and %PM_DISK_TESTPROC
* are always allowed, currently only %PM_DISK_PLATFORM
* makes sense. If the user then choses %PM_DISK_PLATFORM,
* the @prepare call will be called before suspending to disk
* (if present), the @enter call should be present and will
* be called after all state has been saved and the machine
* is ready to be shut down/suspended/..., and the @finish
* callback is called after state has been restored. All
* these calls are called with %PM_SUSPEND_DISK as the state.
* @pm_disk_mode: The generic code always allows one of the shutdown methods
* %PM_DISK_SHUTDOWN, %PM_DISK_REBOOT, %PM_DISK_TEST and
* %PM_DISK_TESTPROC. If this variable is set, the mode it is set
* to is allowed in addition to those modes and is also made default.
* When this mode is sent selected, the @prepare call will be called
* before suspending to disk (if present), the @enter call should be
* present and will be called after all state has been saved and the
* machine is ready to be powered off; the @finish callback is called
* after state has been restored. All these calls are called with
* %PM_SUSPEND_DISK as the state.
*/
struct pm_ops {
int (*valid)(suspend_state_t state);