[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 @@
}
/**
+ * 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.
*