From fe0c935a6cbf25d72a27c7a345df8a2151de0b74 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 30 Apr 2007 15:09:51 -0700 Subject: 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 Cc: David Brownell Acked-by: Pavel Machek Cc: Cc: Len Brown Acked-by: Russell King Cc: Greg KH Cc: "Rafael J. Wysocki" Acked-by: Paul Mundt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/disk.c | 60 ++++++++++++++++++++++++++++++++++------------------- kernel/power/main.c | 6 +++++- 2 files changed, 44 insertions(+), 22 deletions(-) (limited to 'kernel') 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 @@ 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 3062e94..053c0a7 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); } -- cgit v1.1