[PATCH] libata: Conditionally set host->max_cmd_len

In preparation for SAS attached SATA devices, which will
not have a libata scsi_host, only setup host->max_cmd_len
if ap->host exists.

Signed-off-by: Brian King <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/scsi/libata-core.c

···
 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
 }
 
+static void ata_set_port_max_cmd_len(struct ata_port *ap)
+{
+	int i;
+
+	if (ap->host) {
+		ap->host->max_cmd_len = 0;
+		for (i = 0; i < ATA_MAX_DEVICES; i++)
+			ap->host->max_cmd_len = max_t(unsigned int,
+						      ap->host->max_cmd_len,
+						      ap->device[i].cdb_len);
+	}
+}
+
 /**
  *	ata_dev_configure - Configure the specified ATA/ATAPI device
  *	@dev: Target device to configure
···
 	struct ata_port *ap = dev->ap;
 	const u16 *id = dev->id;
 	unsigned int xfer_mask;
-	int i, rc;
+	int rc;
 
 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
 		ata_dev_printk(dev, KERN_INFO,
···
 				       cdb_intr_string);
 	}
 
-	ap->host->max_cmd_len = 0;
-	for (i = 0; i < ATA_MAX_DEVICES; i++)
-		ap->host->max_cmd_len = max_t(unsigned int,
-					      ap->host->max_cmd_len,
-					      ap->device[i].cdb_len);
+	ata_set_port_max_cmd_len(ap);
 
 	/* limit bridge transfers to udma5, 200 sectors */
 	if (ata_dev_knobble(dev)) {