From ebdfca6eb1b755d3bfe9a81339ecdafd92038c1a Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: Thu, 23 Mar 2006 15:38:34 +0000
Subject: [PATCH] libata: add ata_dev_pair helper

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index d8f77f2..909568f 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1576,6 +1576,23 @@ void sata_phy_reset(struct ata_port *ap)
 }
 
 /**
+ *	ata_dev_pair		-	return other device on cable
+ *	@ap: port
+ *	@adev: device
+ *
+ *	Obtain the other device on the same cable, or if none is
+ *	present NULL is returned
+ */
+ 
+struct ata_device *ata_dev_pair(struct ata_port *ap, struct ata_device *adev)
+{
+	struct ata_device *pair = &ap->device[1 - adev->devno];
+	if (!ata_dev_present(pair))
+		return NULL;
+	return pair;
+}
+
+/**
  *	ata_port_disable - Disable port.
  *	@ap: Port to be disabled.
  *
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c52f134..80c2339 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -573,6 +573,8 @@ extern int ata_std_bios_param(struct scsi_device *sdev,
 			      struct block_device *bdev,
 			      sector_t capacity, int geom[]);
 extern int ata_scsi_slave_config(struct scsi_device *sdev);
+extern struct ata_device *ata_dev_pair(struct ata_port *ap, 
+				       struct ata_device *adev);
 
 /*
  * Timing helpers
-- 
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