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Commit 620b0327 authored by Pavel Machek's avatar Pavel Machek Committed by Linus Torvalds
Browse files

[PATCH] properly stop devices before poweroff 



Without this patch, Linux provokes emergency disk shutdowns and
similar nastiness. It was in SuSE kernels for some time, IIRC.

Signed-off-by: default avatarPavel Machek <pavel@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 5ce47e59

include/linux/pm.h

+21 −12
Original line number Diff line number Diff line
@@ -103,7 +103,8 @@ extern int pm_active; 
/*

 * Register a device with power management

 */

struct pm_dev __deprecated *pm_register(pm_dev_t type, unsigned long id, pm_callback callback);

struct pm_dev __deprecated *

pm_register(pm_dev_t type, unsigned long id, pm_callback callback);



/*

 * Unregister a device with power management
@@ -190,17 +191,18 @@ typedef u32 __bitwise pm_message_t; 
/*

 * There are 4 important states driver can be in:

 * ON     -- driver is working

 * FREEZE -- stop operations and apply whatever policy is applicable to a suspended driver

 *           of that class, freeze queues for block like IDE does, drop packets for

 *           ethernet, etc... stop DMA engine too etc... so a consistent image can be

 *           saved; but do not power any hardware down.

 * SUSPEND - like FREEZE, but hardware is doing as much powersaving as possible. Roughly

 *           pci D3.

 * FREEZE -- stop operations and apply whatever policy is applicable to a

 *           suspended driver of that class, freeze queues for block like IDE

 *           does, drop packets for ethernet, etc... stop DMA engine too etc...

 *           so a consistent image can be saved; but do not power any hardware

 *           down.

 * SUSPEND - like FREEZE, but hardware is doing as much powersaving as

 *           possible. Roughly pci D3.

 *

 * Unfortunately, current drivers only recognize numeric values 0 (ON) and 3 (SUSPEND).

 * We'll need to fix the drivers. So yes, putting 3 to all diferent defines is intentional,

 * and will go away as soon as drivers are fixed. Also note that typedef is neccessary,

 * we'll probably want to switch to

 * Unfortunately, current drivers only recognize numeric values 0 (ON) and 3

 * (SUSPEND).  We'll need to fix the drivers. So yes, putting 3 to all different

 * defines is intentional, and will go away as soon as drivers are fixed.  Also

 * note that typedef is neccessary, we'll probably want to switch to

 *   typedef struct pm_message_t { int event; int flags; } pm_message_t

 * or something similar soon.

 */
@@ -222,11 +224,18 @@ struct dev_pm_info { 


extern void device_pm_set_parent(struct device * dev, struct device * parent);



extern int device_suspend(pm_message_t state);

extern int device_power_down(pm_message_t state);

extern void device_power_up(void);

extern void device_resume(void);



#ifdef CONFIG_PM

extern int device_suspend(pm_message_t state);

#else

static inline int device_suspend(pm_message_t state)

{

	return 0;

}

#endif



#endif /* __KERNEL__ */

kernel/sys.c

+3 −0
Original line number Diff line number Diff line
@@ -405,6 +405,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user 
	case LINUX_REBOOT_CMD_HALT:

		notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);

		system_state = SYSTEM_HALT;

		device_suspend(PMSG_SUSPEND);

		device_shutdown();

		printk(KERN_EMERG "System halted.\n");

		machine_halt();
@@ -415,6 +416,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user 
	case LINUX_REBOOT_CMD_POWER_OFF:

		notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);

		system_state = SYSTEM_POWER_OFF;

		device_suspend(PMSG_SUSPEND);

		device_shutdown();

		printk(KERN_EMERG "Power down.\n");

		machine_power_off();
@@ -431,6 +433,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user 


		notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);

		system_state = SYSTEM_RESTART;

		device_suspend(PMSG_FREEZE);

		device_shutdown();

		printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);

		machine_restart(buffer);