[PATCH] libata basic detection and errata for PATA->SATA bridges

This patch works around an issue with WD drives (and possibly others)
over SiL PATA->SATA Bridges on SATA controllers locking up with
transfers > 200 sectors.

Signed-off-by: Brad Campbell <brad@wasp.net.au>

drivers/scsi/libata-core.c

@@ -1186,6 +1186,37 @@ err_out:
 	DPRINTK("EXIT, err\n");
 }
 
+
+static inline u8 ata_dev_knobble(struct ata_port *ap)
+{
+	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(ap->device->id)));
+}
+
+/**
+ * 	ata_dev_config - Run device specific handlers and check for
+ * 			 SATA->PATA bridges
+ * 	@ap: Bus 
+ * 	@i:  Device
+ *
+ * 	LOCKING:
+ */
+ 
+void ata_dev_config(struct ata_port *ap, unsigned int i)
+{
+	/* limit bridge transfers to udma5, 200 sectors */
+	if (ata_dev_knobble(ap)) {
+		printk(KERN_INFO "ata%u(%u): applying bridge limits\n",
+			ap->id, ap->device->devno);
+		ap->udma_mask &= ATA_UDMA5;
+		ap->host->max_sectors = ATA_MAX_SECTORS;
+		ap->host->hostt->max_sectors = ATA_MAX_SECTORS;
+		ap->device->flags |= ATA_DFLAG_LOCK_SECTORS;
+	}
+
+	if (ap->ops->dev_config)
+		ap->ops->dev_config(ap, &ap->device[i]);
+}
+
 /**
  *	ata_bus_probe - Reset and probe ATA bus
  *	@ap: Bus to probe
@@ -1208,8 +1239,7 @@ static int ata_bus_probe(struct ata_port *ap)
 		ata_dev_identify(ap, i);
 		if (ata_dev_present(&ap->device[i])) {
 			found = 1;
-			if (ap->ops->dev_config)
-				ap->ops->dev_config(ap, &ap->device[i]);
+			ata_dev_config(ap,i);
 		}
 	}
 
@@ -4014,6 +4044,7 @@ EXPORT_SYMBOL_GPL(ata_scsi_release);
 EXPORT_SYMBOL_GPL(ata_host_intr);
 EXPORT_SYMBOL_GPL(ata_dev_classify);
 EXPORT_SYMBOL_GPL(ata_dev_id_string);
+EXPORT_SYMBOL_GPL(ata_dev_config);
 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
 
 #ifdef CONFIG_PCI