Solving suspend-level confusion

[Pavel Machek <pavel@suse.cz>]

Hi!

There's quite big confusion what 'u32 state' in suspend callbacks
mean. Half code interprets it as a system-wide suspend level, and
second half thinks it is PCI Dx state. Bad.

What about this solution:

* system-wide suspend level is always passed down (it is more
detailed, and for example IDE driver cares)

* if you want to derive Dx state, just use provided inline function to
convert.

That should be acceptable to everyone. I plan on explicitly using
enums to prevent further confusion. Patch is likely to be pretty big:
ideally all prototypes of suspend function would be fixed so noone can
be confused.

What do you think?
								Pavel
PS: I'll be on holidays for a week, feel free to implement this or
something similar.. it is going to be lot of search/replace in drivers
:-(.

--- tmp/linux/include/linux/pci.h	2004-06-22 12:36:45.000000000 +0200
+++ linux/include/linux/pci.h	2004-07-30 18:24:02.000000000 +0200
@@ -593,7 +593,7 @@
 	const struct pci_device_id *id_table;	/* must be non-NULL for probe to be called */
 	int  (*probe)  (struct pci_dev *dev, const struct pci_device_id *id);	/* New device inserted */
 	void (*remove) (struct pci_dev *dev);	/* Device removed (NULL if not a hot-plug capable driver) */
-	int  (*suspend) (struct pci_dev *dev, u32 state);	/* Device suspended */
+	int  (*suspend) (struct pci_dev *dev, enum suspend_state reason);	/* Device suspended */
 	int  (*resume) (struct pci_dev *dev);	                /* Device woken up */
 	int  (*enable_wake) (struct pci_dev *dev, u32 state, int enable);   /* Enable wake event */
 
--- tmp/linux/include/linux/pm.h	2004-06-22 12:36:45.000000000 +0200
+++ linux/include/linux/pm.h	2004-07-30 18:23:11.000000000 +0200
@@ -193,11 +193,11 @@
 extern void (*pm_idle)(void);
 extern void (*pm_power_off)(void);
 
-enum {
-	PM_SUSPEND_ON,
-	PM_SUSPEND_STANDBY,
-	PM_SUSPEND_MEM,
-	PM_SUSPEND_DISK,
+enum system_state {
+	PM_SUSPEND_ON = 0,
+	PM_SUSPEND_STANDBY = 1,
+	PM_SUSPEND_MEM = 2,
+	PM_SUSPEND_DISK = 3,
 	PM_SUSPEND_MAX,
 };
 
@@ -241,11 +240,47 @@
 
 extern void device_pm_set_parent(struct device * dev, struct device * parent);
 
-extern int device_suspend(u32 state);
-extern int device_power_down(u32 state);
+enum suspend_state {
+	SNAPSHOT = 10,		/* For debugging, symbolic constants should be everywhere */
+	POWERDOWN,
+	RESTART,
+	RUNTIME_D1,
+	RUNTIME_D2,
+	RUNTIME_D3hot,
+	RUNTIME_D3cold
+};
+
+extern int device_suspend(enum suspend_state reason);
+extern int device_power_down(enum suspend_state reason);
 extern void device_power_up(void);
 extern void device_resume(void);
 
+enum pci_state {
+	D0 = 20,		/* For debugging, symbolic constants should be everywhere */
+	D1,
+	D2,
+	D3hot,
+	D3cold
+};
+
+static inline enum pci_state to_pci_state(enum suspend_state state)
+{
+	switch(state) {
+	case RUNTIME_D1:
+		return D1;
+	case RUNTIME_D2:
+		return D2;
+	case RUNTIME_D3hot:
+		return D3hot;
+	case SNAPSHOT:
+	case POWERDOWN:
+	case RESTART:
+	case RUNTIME_D3cold:
+		return D3cold;
+	default:
+		BUG();
+	}
+}
 
 #endif /* __KERNEL__ */
 
--- tmp/linux/kernel/power/disk.c	2004-05-20 23:08:36.000000000 +0200
+++ linux/kernel/power/disk.c	2004-07-30 18:18:04.000000000 +0200
@@ -46,20 +46,25 @@
 	int error = 0;
 
 	local_irq_save(flags);
-	device_power_down(PM_SUSPEND_DISK);
 	switch(mode) {
 	case PM_DISK_PLATFORM:
+		device_power_down(POWERDOWN);
 		error = pm_ops->enter(PM_SUSPEND_DISK);
 		break;
 	case PM_DISK_SHUTDOWN:
+		device_power_down(POWERDOWN);
 		printk("Powering off system\n");
 		machine_power_off();
 		break;
 	case PM_DISK_REBOOT:
+		device_power_down(RESTART);
 		machine_restart(NULL);
 		break;
 	}
 	machine_halt();
+	/* Valid image is on the disk, if we continue we risk serious data corruption
+	   after resume. */
+	while(1);
 	device_power_up();
 	local_irq_restore(flags);
 	return 0;

-- 
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