+ rework-pm_ops-pm_disk_mode-kill-misuse.patch added to -mm tree

akpm
2007-03-22T18:00:55Z

The patch titled
rework pm_ops pm_disk_mode, kill misuse
has been added to the -mm tree. Its filename is
rework-pm_ops-pm_disk_mode-kill-misuse.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: rework pm_ops pm_disk_mode, kill misuse
From: Johannes Berg <johannes@sipsolutions.net>

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>
---

arch/arm/common/sharpsl_pm.c | 1
arch/arm/mach-at91/pm.c | 1
arch/arm/mach-omap1/pm.c | 1
arch/arm/mach-omap2/pm.c | 1
arch/arm/mach-pxa/pm.c | 4 --
arch/arm/mach-sa1100/pm.c | 7 ----
arch/arm/plat-s3c24xx/pm.c | 9 -----
arch/sh/boards/hp6xx/pm.c | 7 ----
include/linux/pm.h | 23 +++++++------
kernel/power/disk.c | 56 +++++++++++++++++++++------------
kernel/power/main.c | 6 ++-
11 files changed, 54 insertions(+), 62 deletions(-)

diff -puN arch/arm/common/sharpsl_pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/common/sharpsl_pm.c
--- a/arch/arm/common/sharpsl_pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/common/sharpsl_pm.c
@@ -766,7 +766,6 @@ static void sharpsl_apm_get_power_status
}

static struct pm_ops sharpsl_pm_ops = {
- .pm_disk_mode = PM_DISK_FIRMWARE,
.prepare = pxa_pm_prepare,
.enter = corgi_pxa_pm_enter,
.finish = pxa_pm_finish,
diff -puN arch/arm/mach-at91/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/mach-at91/pm.c
--- a/arch/arm/mach-at91/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/mach-at91/pm.c
@@ -201,7 +201,6 @@ error:

static struct pm_ops at91_pm_ops ={
- .pm_disk_mode = 0,
.valid = at91_pm_valid_state,
.prepare = at91_pm_prepare,
.enter = at91_pm_enter,
diff -puN arch/arm/mach-omap1/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/mach-omap1/pm.c
--- a/arch/arm/mach-omap1/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/mach-omap1/pm.c
@@ -698,7 +698,6 @@ static struct irqaction omap_wakeup_irq

static struct pm_ops omap_pm_ops ={
- .pm_disk_mode = 0,
.prepare = omap_pm_prepare,
.enter = omap_pm_enter,
.finish = omap_pm_finish,
diff -puN arch/arm/mach-omap2/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/mach-omap2/pm.c
--- a/arch/arm/mach-omap2/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/mach-omap2/pm.c
@@ -370,7 +370,6 @@ static int omap2_pm_finish(suspend_state
}

static struct pm_ops omap_pm_ops = {
- .pm_disk_mode = 0,
.prepare = omap2_pm_prepare,
.enter = omap2_pm_enter,
.finish = omap2_pm_finish,
diff -puN arch/arm/mach-pxa/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/mach-pxa/pm.c
--- a/arch/arm/mach-pxa/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/mach-pxa/pm.c
@@ -223,11 +223,7 @@ int pxa_pm_finish(suspend_state_t state)

EXPORT_SYMBOL_GPL(pxa_pm_finish);

-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
static struct pm_ops pxa_pm_ops = {
- .pm_disk_mode = PM_DISK_FIRMWARE,
.prepare = pxa_pm_prepare,
.enter = pxa_pm_enter,
.finish = pxa_pm_finish,
diff -puN arch/arm/mach-sa1100/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/mach-sa1100/pm.c
--- a/arch/arm/mach-sa1100/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/mach-sa1100/pm.c
@@ -59,9 +59,6 @@ static int sa11x0_pm_enter(suspend_state
unsigned long gpio, sleep_save[SLEEP_SAVE_SIZE];
struct timespec delta, rtc;

- if (state != PM_SUSPEND_MEM)
- return -EINVAL;
-
/* preserve current time */
rtc.tv_sec = RCNR;
rtc.tv_nsec = 0;
@@ -134,11 +131,7 @@ unsigned long sleep_phys_sp(void *sp)
return virt_to_phys(sp);
}

-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
static struct pm_ops sa11x0_pm_ops = {
- .pm_disk_mode = PM_DISK_FIRMWARE,
.enter = sa11x0_pm_enter,
};

diff -puN arch/arm/plat-s3c24xx/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/arm/plat-s3c24xx/pm.c
--- a/arch/arm/plat-s3c24xx/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/arm/plat-s3c24xx/pm.c
@@ -511,11 +511,6 @@ static int s3c2410_pm_enter(suspend_stat
return -EINVAL;
}

- if (state != PM_SUSPEND_MEM) {
- printk(KERN_ERR PFX "error: only PM_SUSPEND_MEM supported\n");
- return -EINVAL;
- }
-
/* check if we have anything to wake-up with... bad things seem
* to happen if you suspend with no wakeup (system will often
* require a full power-cycle)
@@ -633,11 +628,7 @@ static int s3c2410_pm_finish(suspend_sta
return 0;
}

-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
static struct pm_ops s3c2410_pm_ops = {
- .pm_disk_mode = PM_DISK_FIRMWARE,
.prepare = s3c2410_pm_prepare,
.enter = s3c2410_pm_enter,
.finish = s3c2410_pm_finish,
diff -puN arch/sh/boards/hp6xx/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse arch/sh/boards/hp6xx/pm.c
--- a/arch/sh/boards/hp6xx/pm.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/arch/sh/boards/hp6xx/pm.c
@@ -27,9 +27,6 @@ static int hp6x0_pm_enter(suspend_state_
u16 hd64461_stbcr;
#endif

- if (state != PM_SUSPEND_MEM)
- return -EINVAL;
-
#ifdef CONFIG_HD64461_ENABLER
outb(0, HD64461_PCC1CSCIER);

@@ -70,11 +67,7 @@ static int hp6x0_pm_enter(suspend_state_
return 0;
}

-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
static struct pm_ops hp6x0_pm_ops = {
- .pm_disk_mode = PM_DISK_FIRMWARE,
.enter = hp6x0_pm_enter,
};

diff -puN include/linux/pm.h~rework-pm_ops-pm_disk_mode-kill-misuse include/linux/pm.h
--- a/include/linux/pm.h~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/include/linux/pm.h
@@ -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_metho
* @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);
diff -puN kernel/power/disk.c~rework-pm_ops-pm_disk_mode-kill-misuse kernel/power/disk.c
--- a/kernel/power/disk.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/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);
}
@@ -48,31 +54,33 @@ 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)
{
disable_nonboot_cpus();
- 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. */
@@ -82,7 +90,13 @@ static void power_down(suspend_disk_meth

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);
}
@@ -177,7 +191,7 @@ 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;
@@ -365,10 +379,14 @@ static ssize_t disk_store(struct subsyst
}
}
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 -puN kernel/power/main.c~rework-pm_ops-pm_disk_mode-kill-misuse kernel/power/main.c
--- a/kernel/power/main.c~rework-pm_ops-pm_disk_mode-kill-misuse
+++ a/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);
}

_

Patches currently in -mm which might be from johannes@sipsolutions.net are

origin.patch
git-alsa.patch
git-wireless.patch
rework-pm_ops-pm_disk_mode-kill-misuse.patch
power-management-remove-firmware-disk-mode.patch
power-management-implement-pm_opsvalid-for-everybody.patch
power-management-force-pm_opsvalid-callback-to-be.patch