ide: hook ACPI _PSx method to IDE power on/off

ACPI spec defines the sequence of IDE power on/off:
Powering down:
	Call _GTM.
	Power down drive (calls _PS3 method and turns off power planes).
Powering up:
	Power up drive (calls _PS0 method if present and turns on power planes).
	Call _STM passing info from _GTM (possibly modified), with ID data from
	each drive.
	Initialize the channel.
	May modify the results of _GTF.
	For each drive:
		Call _GTF.
		Execute task file (possibly modified).
This patch adds the missed _PS0/_PS3 methods call.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

3 files changed, 57 insertions, 3 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9ba778a..feab124 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -262,10 +262,12 @@ int acpi_bus_set_power(acpi_handle handle, int state)
 		printk(KERN_WARNING PREFIX
 			      "Transitioning device [%s] to D%d\n",
 			      device->pnp.bus_id, state);
-	else
+	else {
+		device->power.state = state;
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 				  "Device [%s] transitioned to D%d\n",
 				  device->pnp.bus_id, state));
+	}
 
 	return result;
 }
diff --git a/drivers/ide/ide-acpi.c b/drivers/ide/ide-acpi.c
index 17aea65..6bff81a 100644
--- a/drivers/ide/ide-acpi.c
+++ b/drivers/ide/ide-acpi.c
@@ -612,6 +612,46 @@ void ide_acpi_push_timing(ide_hwif_t *hwif)
 EXPORT_SYMBOL_GPL(ide_acpi_push_timing);
 
 /**
+ * ide_acpi_set_state - set the channel power state
+ * @hwif: target IDE interface
+ * @on: state, on/off
+ *
+ * This function executes the _PS0/_PS3 ACPI method to set the power state.
+ * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
+ */
+void ide_acpi_set_state(ide_hwif_t *hwif, int on)
+{
+	int unit;
+
+	if (ide_noacpi)
+		return;
+
+	DEBPRINT("ENTER:\n");
+
+	if (!hwif->acpidata) {
+		DEBPRINT("no ACPI data for %s\n", hwif->name);
+		return;
+	}
+	/* channel first and then drives for power on and verse versa for power off */
+	if (on)
+		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		ide_drive_t *drive = &hwif->drives[unit];
+
+		if (!drive->acpidata->obj_handle)
+			drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
+
+		if (drive->acpidata->obj_handle && drive->present) {
+			acpi_bus_set_power(drive->acpidata->obj_handle,
+				on? ACPI_STATE_D0: ACPI_STATE_D3);
+		}
+	}
+	if (!on)
+		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
+}
+EXPORT_SYMBOL_GPL(ide_acpi_set_state);
+
+/**
  * ide_acpi_init - initialize the ACPI link for an IDE interface
  * @hwif: target IDE interface (channel)
  *
@@ -679,6 +719,8 @@ void ide_acpi_init(ide_hwif_t *hwif)
 		return;
 	}
 
+	/* ACPI _PS0 before _STM */
+	ide_acpi_set_state(hwif, 1);
 	/*
 	 * ACPI requires us to call _STM on startup
 	 */
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index de54306..9fdc1fe 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -915,6 +915,7 @@ static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 	struct request rq;
 	struct request_pm_state rqpm;
 	ide_task_t args;
+	int ret;
 
 	/* Call ACPI _GTM only once */
 	if (!(drive->dn % 2))
@@ -931,7 +932,14 @@ static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 		mesg.event = PM_EVENT_FREEZE;
 	rqpm.pm_state = mesg.event;
 
-	return ide_do_drive_cmd(drive, &rq, ide_wait);
+	ret = ide_do_drive_cmd(drive, &rq, ide_wait);
+	/* only call ACPI _PS3 after both drivers are suspended */
+	if (!ret && (((drive->dn % 2) && hwif->drives[0].present
+		 && hwif->drives[1].present)
+		 || !hwif->drives[0].present
+		 || !hwif->drives[1].present))
+		ide_acpi_set_state(hwif, 0);
+	return ret;
 }
 
 static int generic_ide_resume(struct device *dev)
@@ -944,8 +952,10 @@ static int generic_ide_resume(struct device *dev)
 	int err;
 
 	/* Call ACPI _STM only once */
-	if (!(drive->dn % 2))
+	if (!(drive->dn % 2)) {
+		ide_acpi_set_state(hwif, 1);
 		ide_acpi_push_timing(hwif);
+	}
 
 	ide_acpi_exec_tfs(drive);