diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 1c33f78..f6d80e3 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -60,7 +60,8 @@
 	if (ap->flags & ATA_FLAG_ACPI_SATA)
 		return NULL;
 
-	return acpi_get_child(DEVICE_ACPI_HANDLE(ap->host->dev), ap->port_no);
+	return ap->scsi_host ?
+		DEVICE_ACPI_HANDLE(&ap->scsi_host->shost_gendev) : NULL;
 }
 EXPORT_SYMBOL(ata_ap_acpi_handle);
 
@@ -239,28 +240,15 @@
 	}
 }
 
-/**
- * ata_acpi_gtm - execute _GTM
- * @ap: target ATA port
- * @gtm: out parameter for _GTM result
- *
- * Evaluate _GTM and store the result in @gtm.
- *
- * LOCKING:
- * EH context.
- *
- * RETURNS:
- * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
- */
-int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)
+static int __ata_acpi_gtm(struct ata_port *ap, acpi_handle handle,
+			  struct ata_acpi_gtm *gtm)
 {
 	struct acpi_buffer output = { .length = ACPI_ALLOCATE_BUFFER };
 	union acpi_object *out_obj;
 	acpi_status status;
 	int rc = 0;
 
-	status = acpi_evaluate_object(ata_ap_acpi_handle(ap), "_GTM", NULL,
-				      &output);
+	status = acpi_evaluate_object(handle, "_GTM", NULL, &output);
 
 	rc = -ENOENT;
 	if (status == AE_NOT_FOUND)
@@ -294,6 +282,27 @@
 	return rc;
 }
 
+/**
+ * ata_acpi_gtm - execute _GTM
+ * @ap: target ATA port
+ * @gtm: out parameter for _GTM result
+ *
+ * Evaluate _GTM and store the result in @gtm.
+ *
+ * LOCKING:
+ * EH context.
+ *
+ * RETURNS:
+ * 0 on success, -ENOENT if _GTM doesn't exist, -errno on failure.
+ */
+int ata_acpi_gtm(struct ata_port *ap, struct ata_acpi_gtm *gtm)
+{
+	if (ata_ap_acpi_handle(ap))
+		return __ata_acpi_gtm(ap, ata_ap_acpi_handle(ap), gtm);
+	else
+		return -EINVAL;
+}
+
 EXPORT_SYMBOL_GPL(ata_acpi_gtm);
 
 /**
@@ -1047,7 +1056,7 @@
 	if (!*handle)
 		return -ENODEV;
 
-	if (ata_acpi_gtm(ap, &ap->__acpi_init_gtm) == 0)
+	if (__ata_acpi_gtm(ap, *handle, &ap->__acpi_init_gtm) == 0)
 		ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;
 
 	return 0;