[PATCH v3] ACPI: D3 states cleanup

[Lin Ming <ming.m.lin@intel.com>]

There are two ACPI D3 states defined now:
ACPI_STATE_D3 and ACPI_STATE_D3_COLD.

But the uses of these states are not clear/correct in some code.
For example, some code refer ACPI_STATE_D3 as D3hot and others refer
it as D3cold.

This patch introduces ACPI_STATE_D3_HOT to refer to ACPI D3hot state.
D3hot is only valid if _PR3 present.
And changes ACPI_STATE_D3 to refer to ACPI D3cold state only.
Also redefines ACPI_STATE_D3_COLD the same as ACPI_STATE_D3.

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---

v3: D3hot is only valid if _PR3 present

 drivers/acpi/power.c   |    2 +-
 drivers/acpi/scan.c    |   17 +++++++----------
 drivers/pci/pci-acpi.c |    4 ++--
 include/acpi/actypes.h |    7 ++++---
 4 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 7049a7d..330bb4d 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -631,7 +631,7 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 	 * We know a device's inferred power state when all the resources
 	 * required for a given D-state are 'on'.
 	 */
-	for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
+	for (i = ACPI_STATE_D0; i < ACPI_STATE_D3_HOT; i++) {
 		list = &device->power.states[i].resources;
 		if (list->count < 1)
 			continue;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 767e2dc..7417267 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -869,7 +869,7 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
 	/*
 	 * Enumerate supported power management states
 	 */
-	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
+	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 		struct acpi_device_power_state *ps = &device->power.states[i];
 		char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
 
@@ -884,21 +884,18 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
 				acpi_bus_add_power_resource(ps->resources.handles[j]);
 		}
 
-		/* The exist of _PR3 indicates D3Cold support */
-		if (i == ACPI_STATE_D3) {
-			status = acpi_get_handle(device->handle, object_name, &handle);
-			if (ACPI_SUCCESS(status))
-				device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
-		}
-
 		/* Evaluate "_PSx" to see if we can do explicit sets */
 		object_name[2] = 'S';
 		status = acpi_get_handle(device->handle, object_name, &handle);
 		if (ACPI_SUCCESS(status))
 			ps->flags.explicit_set = 1;
 
-		/* State is valid if we have some power control */
-		if (ps->resources.count || ps->flags.explicit_set)
+		/*
+		 * State is valid if there are means to put the device into it.
+		 * D3hot is only valid if _PR3 present.
+		 */
+		if (ps->resources.count ||
+		    (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT))
 			ps->flags.valid = 1;
 
 		ps->power = -1;	/* Unknown - driver assigned */
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0f150f2..1929c0c 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -200,7 +200,7 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 		return PCI_D1;
 	case ACPI_STATE_D2:
 		return PCI_D2;
-	case ACPI_STATE_D3:
+	case ACPI_STATE_D3_HOT:
 		return PCI_D3hot;
 	case ACPI_STATE_D3_COLD:
 		return PCI_D3cold;
@@ -223,7 +223,7 @@ static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 		[PCI_D0] = ACPI_STATE_D0,
 		[PCI_D1] = ACPI_STATE_D1,
 		[PCI_D2] = ACPI_STATE_D2,
-		[PCI_D3hot] = ACPI_STATE_D3,
+		[PCI_D3hot] = ACPI_STATE_D3_HOT,
 		[PCI_D3cold] = ACPI_STATE_D3
 	};
 	int error = -EINVAL;
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index eba6604..e8bcc47 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -499,9 +499,10 @@ typedef u64 acpi_integer;
 #define ACPI_STATE_D0                   (u8) 0
 #define ACPI_STATE_D1                   (u8) 1
 #define ACPI_STATE_D2                   (u8) 2
-#define ACPI_STATE_D3                   (u8) 3
-#define ACPI_STATE_D3_COLD              (u8) 4
-#define ACPI_D_STATES_MAX               ACPI_STATE_D3_COLD
+#define ACPI_STATE_D3_HOT               (u8) 3
+#define ACPI_STATE_D3                   (u8) 4
+#define ACPI_STATE_D3_COLD              ACPI_STATE_D3
+#define ACPI_D_STATES_MAX               ACPI_STATE_D3
 #define ACPI_D_STATE_COUNT              5
 
 #define ACPI_STATE_C0                   (u8) 0
-- 
1.7.2.5