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 <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>

drivers/ata/ahci.c

@@ -250,10 +250,6 @@ static struct scsi_host_template ahci_sht = {
 	.slave_configure	= ata_scsi_slave_config,
 	.slave_destroy		= ata_scsi_slave_destroy,
 	.bios_param		= ata_std_bios_param,
-#ifdef CONFIG_PM
-	.suspend		= ata_scsi_device_suspend,
-	.resume			= ata_scsi_device_resume,
-#endif
 };
 
 static const struct ata_port_operations ahci_ops = {

drivers/ata/ata_generic.c

@@ -54,7 +54,7 @@ static int generic_set_mode(struct ata_port *ap, struct ata_device **unused)
 
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct ata_device *dev = &ap->device[i];
-		if (ata_dev_ready(dev)) {
+		if (ata_dev_enabled(dev)) {
 			/* We don't really care */
 			dev->pio_mode = XFER_PIO_0;
 			dev->dma_mode = XFER_MW_DMA_0;
@@ -90,10 +90,6 @@ static struct scsi_host_template generic_sht = {
 	.slave_configure	= ata_scsi_slave_config,
 	.slave_destroy		= ata_scsi_slave_destroy,
 	.bios_param		= ata_std_bios_param,
-#ifdef CONFIG_PM
-	.resume			= ata_scsi_device_resume,
-	.suspend		= ata_scsi_device_suspend,
-#endif
 };
 
 static struct ata_port_operations generic_port_ops = {

drivers/ata/ata_piix.c

@@ -275,10 +275,6 @@ static struct scsi_host_template piix_sht = {
 	.slave_configure	= ata_scsi_slave_config,
 	.slave_destroy		= ata_scsi_slave_destroy,
 	.bios_param		= ata_std_bios_param,
-#ifdef CONFIG_PM
-	.resume			= ata_scsi_device_resume,
-	.suspend		= ata_scsi_device_suspend,
-#endif
 };
 
 static const struct ata_port_operations piix_pata_ops = {

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);