libata: tell scsi layer device supports runtime power off

If ATA device supports "Device Attention", then tell scsi layer that
the device supports runtime power off.

Signed-off-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

2 files changed, 27 insertions, 2 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index f36284e3290d..f1d6901de37d 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -1000,7 +1000,10 @@ static void ata_acpi_add_pm_notifier(struct ata_device *dev)
                 return;
 
         status = acpi_bus_get_device(handle, &acpi_dev);
-        if (ACPI_SUCCESS(status)) {
+        if (ACPI_FAILURE(status))
+                return;
+
+        if (dev->sdev->can_power_off) {
                 acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
                         ata_acpi_wake_dev, dev);
                 device_set_run_wake(&dev->sdev->sdev_gendev, true);
@@ -1018,7 +1021,10 @@ static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
                 return;
 
         status = acpi_bus_get_device(handle, &acpi_dev);
-        if (ACPI_SUCCESS(status)) {
+        if (ACPI_FAILURE(status))
+                return;
+
+        if (dev->sdev->can_power_off) {
                 device_set_run_wake(&dev->sdev->sdev_gendev, false);
                 acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
                         ata_acpi_wake_dev);
@@ -1102,6 +1108,9 @@ static int ata_acpi_bind_device(struct ata_port *ap, struct scsi_device *sdev,
                                 acpi_handle *handle)
 {
         struct ata_device *ata_dev;
+        acpi_status status;
+        struct acpi_device *acpi_dev;
+        struct acpi_device_power_state *states;
 
         if (ap->flags & ATA_FLAG_ACPI_SATA)
                 ata_dev = &ap->link.device[sdev->channel];
@@ -1113,6 +1122,21 @@ static int ata_acpi_bind_device(struct ata_port *ap, struct scsi_device *sdev,
         if (!*handle)
                 return -ENODEV;
 
+        status = acpi_bus_get_device(*handle, &acpi_dev);
+        if (ACPI_FAILURE(status))
+                return 0;
+
+        /*
+         * If firmware has _PS3 or _PR3 for this device,
+         * and this ata ODD device support device attention,
+         * it means this device can be powered off
+         */
+        states = acpi_dev->power.states;
+        if ((states[ACPI_STATE_D3_HOT].flags.valid ||
+                        states[ACPI_STATE_D3_COLD].flags.explicit_set) &&
+                        ata_dev->flags & ATA_DFLAG_DA)
+                sdev->can_power_off = 1;
+
         return 0;
 }
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ba9698852321..aff7525de194 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -153,6 +153,7 @@ struct scsi_device {
         unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
         unsigned try_rc_10_first:1;     /* Try READ_CAPACACITY_10 first */
         unsigned is_visible:1;  /* is the device visible in sysfs */
+        unsigned can_power_off:1; /* Device supports runtime power off */
 
         DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
         struct list_head event_list;    /* asserted events */