libata: reimplement suspend/resume support using sdev->manage_start_stop

Reimplement suspend/resume support using sdev->manage_start_stop.

* Device suspend/resume is now SCSI layer's responsibility and the
  code is simplified a lot.

* DPM is dropped.  This also simplifies code a lot.  Suspend/resume
  status is port-wide now.

* ata_scsi_device_suspend/resume() and ata_dev_ready() removed.

* Resume now has to wait for disk to spin up before proceeding.  I
  couldn't find easy way out as libata is in EH waiting for the
  disk to be ready and sd is waiting for EH to complete to issue
  START_STOP.

* sdev->manage_start_stop is set to 1 in ata_scsi_slave_config().
  This fixes spindown on shutdown and suspend-to-disk.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 4 insertions, 35 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 4595d1f8cf60..2e2a2fa8e9e9 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2860,7 +2860,7 @@ int ata_do_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
                 dev = &ap->device[i];
 
                 /* don't update suspended devices' xfer mode */
-                if (!ata_dev_ready(dev))
+                if (!ata_dev_enabled(dev))
                         continue;
 
                 rc = ata_dev_set_mode(dev);
@@ -5845,37 +5845,11 @@ static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
  */
 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
 {
-        int i, j, rc;
+        int rc;
 
         rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
-        if (rc)
-                goto fail;
-
-        /* EH is quiescent now.  Fail if we have any ready device.
-         * This happens if hotplug occurs between completion of device
-         * suspension and here.
-         */
-        for (i = 0; i < host->n_ports; i++) {
-                struct ata_port *ap = host->ports[i];
-
-                for (j = 0; j < ATA_MAX_DEVICES; j++) {
-                        struct ata_device *dev = &ap->device[j];
-
-                        if (ata_dev_ready(dev)) {
-                                ata_port_printk(ap, KERN_WARNING,
-                                                "suspend failed, device %d "
-                                                "still active\n", dev->devno);
-                                rc = -EBUSY;
-                                goto fail;
-                        }
-                }
-        }
-
-        host->dev->power.power_state = mesg;
-        return 0;
-
- fail:
-        ata_host_resume(host);
+        if (rc == 0)
+                host->dev->power.power_state = mesg;
         return rc;
 }
 
@@ -6889,11 +6863,6 @@ EXPORT_SYMBOL_GPL(ata_pci_default_filter);
 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
 #endif /* CONFIG_PCI */
 
-#ifdef CONFIG_PM
-EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
-EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
-#endif /* CONFIG_PM */
-
 EXPORT_SYMBOL_GPL(ata_eng_timeout);
 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
 EXPORT_SYMBOL_GPL(ata_port_abort);