diff -rup linux-2.6.15-rc6-orig/drivers/scsi/ata_piix.c linux-2.6.15-rc6-patched/drivers/scsi/ata_piix.c
--- linux-2.6.15-rc6-orig/drivers/scsi/ata_piix.c	2005-12-21 03:04:46.000000000 +0200
+++ linux-2.6.15-rc6-patched/drivers/scsi/ata_piix.c	2005-12-21 03:14:22.000000000 +0200
@@ -125,6 +125,8 @@ static struct pci_driver piix_pci_driver
 	.id_table		= piix_pci_tbl,
 	.probe			= piix_init_one,
 	.remove			= ata_pci_remove_one,
+	.suspend		= ata_pci_device_suspend,
+	.resume			= ata_pci_device_resume,
 };
 
 static struct scsi_host_template piix_sht = {
@@ -145,6 +147,8 @@ static struct scsi_host_template piix_sh
 	.slave_configure	= ata_scsi_slave_config,
 	.bios_param		= ata_std_bios_param,
 	.ordered_flush		= 1,
+	.suspend		= ata_scsi_device_suspend,
+	.resume			= ata_scsi_device_resume,
 };
 
 static const struct ata_port_operations piix_pata_ops = {
diff -rup linux-2.6.15-rc6-orig/drivers/scsi/libata-core.c linux-2.6.15-rc6-patched/drivers/scsi/libata-core.c
--- linux-2.6.15-rc6-orig/drivers/scsi/libata-core.c	2005-12-21 03:04:47.000000000 +0200
+++ linux-2.6.15-rc6-patched/drivers/scsi/libata-core.c	2005-12-21 03:14:22.000000000 +0200
@@ -4099,6 +4099,104 @@ err_out:
 }
 
 
+/*
+ * Execute a 'simple' command, that only consists of the opcode 'cmd' itself,
+ * without filling any other registers
+ */
+static int ata_do_simple_cmd(struct ata_port *ap, struct ata_device *dev,
+			     u8 cmd)
+{
+	DECLARE_COMPLETION(wait);
+	struct ata_queued_cmd *qc;
+	unsigned long flags;
+	int rc;
+
+	while ((qc = ata_qc_new_init(ap, dev)) == NULL)
+		msleep(10);
+
+	qc->tf.command = cmd;
+	qc->tf.flags |= ATA_TFLAG_DEVICE;
+	qc->tf.protocol = ATA_PROT_NODATA;
+
+	qc->waiting = &wait;
+	qc->complete_fn = ata_qc_complete_noop;
+
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+	rc = ata_qc_issue(qc);
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+	if (!rc)
+		wait_for_completion(&wait);
+
+	return rc;
+}
+
+static int ata_flush_cache(struct ata_port *ap, struct ata_device *dev)
+{
+	u8 cmd;
+
+	if (!ata_try_flush_cache(dev))
+		return 0;
+
+	if (ata_id_has_flush_ext(dev->id))
+		cmd = ATA_CMD_FLUSH_EXT;
+	else
+		cmd = ATA_CMD_FLUSH;
+
+	return ata_do_simple_cmd(ap, dev, cmd);
+}
+
+static int ata_standby_drive(struct ata_port *ap, struct ata_device *dev)
+{
+	return ata_do_simple_cmd(ap, dev, ATA_CMD_STANDBYNOW1);
+}
+
+static int ata_start_drive(struct ata_port *ap, struct ata_device *dev)
+{
+	return ata_do_simple_cmd(ap, dev, ATA_CMD_IDLEIMMEDIATE);
+}
+
+/**
+ *	ata_device_resume - wakeup a previously suspended devices
+ *
+ *	Kick the drive back into action, by sending it an idle immediate
+ *	command and making sure its transfer mode matches between drive
+ *	and host.
+ *
+ */
+int ata_device_resume(struct ata_port *ap, struct ata_device *dev)
+{
+	if (ap->flags & ATA_FLAG_SUSPENDED) {
+		ap->flags &= ~ATA_FLAG_SUSPENDED;
+		ata_set_mode(ap);
+	}
+	if (!ata_dev_present(dev))
+		return 0;
+	if (dev->class == ATA_DEV_ATA)
+		ata_start_drive(ap, dev);
+
+	return 0;
+}
+
+/**
+ *	ata_device_suspend - prepare a device for suspend
+ *
+ *	Flush the cache on the drive, if appropriate, then issue a
+ *	standbynow command.
+ *
+ */
+int ata_device_suspend(struct ata_port *ap, struct ata_device *dev)
+{
+	if (!ata_dev_present(dev))
+		return 0;
+	if (dev->class == ATA_DEV_ATA)
+		ata_flush_cache(ap, dev);
+
+	ata_standby_drive(ap, dev);
+	ap->flags |= ATA_FLAG_SUSPENDED;
+	return 0;
+}
+
 /**
  *	ata_port_start - Set port up for dma.
  *	@ap: Port to initialize
@@ -4860,6 +4958,23 @@ int pci_test_config_bits(struct pci_dev 
 
 	return (tmp == bits->val) ? 1 : 0;
 }
+
+int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	pci_save_state(pdev);
+	pci_disable_device(pdev);
+	pci_set_power_state(pdev, PCI_D3hot);
+	return 0;
+}
+
+int ata_pci_device_resume(struct pci_dev *pdev)
+{
+	pci_set_power_state(pdev, PCI_D0);
+	pci_restore_state(pdev);
+	pci_enable_device(pdev);
+	pci_set_master(pdev);
+	return 0;
+}
 #endif /* CONFIG_PCI */
 
 
@@ -4963,4 +5078,11 @@ EXPORT_SYMBOL_GPL(ata_pci_host_stop);
 EXPORT_SYMBOL_GPL(ata_pci_init_native_mode);
 EXPORT_SYMBOL_GPL(ata_pci_init_one);
 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
+EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
+EXPORT_SYMBOL_GPL(ata_pci_device_resume);
 #endif /* CONFIG_PCI */
+
+EXPORT_SYMBOL_GPL(ata_device_suspend);
+EXPORT_SYMBOL_GPL(ata_device_resume);
+EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
+EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
diff -rup linux-2.6.15-rc6-orig/drivers/scsi/libata-scsi.c linux-2.6.15-rc6-patched/drivers/scsi/libata-scsi.c
--- linux-2.6.15-rc6-orig/drivers/scsi/libata-scsi.c	2005-12-21 03:04:47.000000000 +0200
+++ linux-2.6.15-rc6-patched/drivers/scsi/libata-scsi.c	2005-12-21 03:14:22.000000000 +0200
@@ -396,6 +396,22 @@ void ata_dump_status(unsigned id, struct
 	}
 }
 
+int ata_scsi_device_resume(struct scsi_device *sdev)
+{
+	struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
+	struct ata_device *dev = &ap->device[sdev->id];
+
+	return ata_device_resume(ap, dev);
+}
+
+int ata_scsi_device_suspend(struct scsi_device *sdev)
+{
+	struct ata_port *ap = (struct ata_port *) &sdev->host->hostdata[0];
+	struct ata_device *dev = &ap->device[sdev->id];
+
+	return ata_device_suspend(ap, dev);
+}
+
 /**
  *	ata_to_sense_error - convert ATA error to SCSI error
  *	@id: ATA device number
diff -rup linux-2.6.15-rc6-orig/drivers/scsi/scsi_sysfs.c linux-2.6.15-rc6-patched/drivers/scsi/scsi_sysfs.c
--- linux-2.6.15-rc6-orig/drivers/scsi/scsi_sysfs.c	2005-12-21 03:04:47.000000000 +0200
+++ linux-2.6.15-rc6-patched/drivers/scsi/scsi_sysfs.c	2005-12-21 03:14:22.000000000 +0200
@@ -263,9 +263,40 @@ static int scsi_bus_match(struct device 
 	return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
 }
 
+static int scsi_bus_suspend(struct device * dev, pm_message_t state)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct scsi_host_template *sht = sdev->host->hostt;
+	int err;
+
+	err = scsi_device_quiesce(sdev);
+	if (err)
+		return err;
+
+	if (sht->suspend)
+		err = sht->suspend(sdev);
+
+	return err;
+}
+
+static int scsi_bus_resume(struct device * dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct scsi_host_template *sht = sdev->host->hostt;
+	int err = 0;
+
+	if (sht->resume)
+		err = sht->resume(sdev);
+
+	scsi_device_resume(sdev);
+	return err;
+}
+
 struct bus_type scsi_bus_type = {
-        .name		= "scsi",
-        .match		= scsi_bus_match,
+	.name		= "scsi",
+	.match		= scsi_bus_match,
+	.suspend	= scsi_bus_suspend,
+	.resume		= scsi_bus_resume,
 };
 
 int scsi_sysfs_register(void)
diff -rup linux-2.6.15-rc6-orig/include/linux/ata.h linux-2.6.15-rc6-patched/include/linux/ata.h
--- linux-2.6.15-rc6-orig/include/linux/ata.h	2005-12-21 03:04:48.000000000 +0200
+++ linux-2.6.15-rc6-patched/include/linux/ata.h	2005-12-21 03:14:22.000000000 +0200
@@ -141,6 +141,8 @@ enum {
 	ATA_CMD_PACKET		= 0xA0,
 	ATA_CMD_VERIFY		= 0x40,
 	ATA_CMD_VERIFY_EXT	= 0x42,
+ 	ATA_CMD_STANDBYNOW1	= 0xE0,
+ 	ATA_CMD_IDLEIMMEDIATE	= 0xE1,
 	ATA_CMD_INIT_DEV_PARAMS	= 0x91,
 
 	/* SETFEATURES stuff */
diff -rup linux-2.6.15-rc6-orig/include/linux/libata.h linux-2.6.15-rc6-patched/include/linux/libata.h
--- linux-2.6.15-rc6-orig/include/linux/libata.h	2005-12-21 03:04:48.000000000 +0200
+++ linux-2.6.15-rc6-patched/include/linux/libata.h	2005-12-21 03:15:32.000000000 +0200
@@ -123,6 +123,7 @@ enum {
 					     * proper HSM is in place. */
 	ATA_FLAG_DEBUGMSG	= (1 << 10),
 	ATA_FLAG_NO_ATAPI	= (1 << 11), /* No ATAPI support */
+	ATA_FLAG_SUSPENDED	= (1 << 12), /* port is suspended */
 
 	ATA_QCFLAG_ACTIVE	= (1 << 1), /* cmd not yet ack'd to scsi lyer */
 	ATA_QCFLAG_SG		= (1 << 3), /* have s/g table? */
@@ -436,6 +437,8 @@ extern void ata_std_ports(struct ata_iop
 extern int ata_pci_init_one (struct pci_dev *pdev, struct ata_port_info **port_info,
 			     unsigned int n_ports);
 extern void ata_pci_remove_one (struct pci_dev *pdev);
+extern int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t state);
+extern int ata_pci_device_resume(struct pci_dev *pdev);
 #endif /* CONFIG_PCI */
 extern int ata_device_add(const struct ata_probe_ent *ent);
 extern void ata_host_set_remove(struct ata_host_set *host_set);
@@ -445,6 +448,10 @@ extern int ata_scsi_queuecmd(struct scsi
 extern int ata_scsi_error(struct Scsi_Host *host);
 extern int ata_scsi_release(struct Scsi_Host *host);
 extern unsigned int ata_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc);
+extern int ata_scsi_device_resume(struct scsi_device *);
+extern int ata_scsi_device_suspend(struct scsi_device *);
+extern int ata_device_resume(struct ata_port *, struct ata_device *);
+extern int ata_device_suspend(struct ata_port *, struct ata_device *);
 extern int ata_ratelimit(void);
 
 /*
diff -rup linux-2.6.15-rc6-orig/include/scsi/scsi_host.h linux-2.6.15-rc6-patched/include/scsi/scsi_host.h
--- linux-2.6.15-rc6-orig/include/scsi/scsi_host.h	2005-12-21 03:04:48.000000000 +0200
+++ linux-2.6.15-rc6-patched/include/scsi/scsi_host.h	2005-12-21 03:14:22.000000000 +0200
@@ -296,6 +296,12 @@ struct scsi_host_template {
 	int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
 
 	/*
+	 * suspend support
+	 */
+	int (*suspend)(struct scsi_device *);
+	int (*resume)(struct scsi_device *);
+
+	/*
 	 * Name of proc directory
 	 */
 	char *proc_name;