[PATCH] libata: add per-device max_sectors

If a low level driver wants to control max_sectors, it had to adjust
ap->host->max_sectors and set ATA_DFLAG_LOCK_SECTORS to tell
ata_scsi_slave_config not to override the limit.  This is not only
cumbersome but also incorrect for hosts which support more than one
devices per port.

This patch adds per-device ->max_sectors.  If the field is unset
(zero), libata core layer will adjust ->max_sectors according to
default rules.  If the field is set, libata honors the setting.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/scsi/sata_sil.c b/drivers/scsi/sata_sil.c
index 61c4ac7..6c482c8 100644
--- a/drivers/scsi/sata_sil.c
+++ b/drivers/scsi/sata_sil.c
@@ -354,9 +354,7 @@
 	     (quirks & SIL_QUIRK_MOD15WRITE))) {
 		printk(KERN_INFO "ata%u(%u): applying Seagate errata fix (mod15write workaround)\n",
 		       ap->id, dev->devno);
-		ap->host->max_sectors = 15;
-		ap->host->hostt->max_sectors = 15;
-		dev->flags |= ATA_DFLAG_LOCK_SECTORS;
+		dev->max_sectors = 15;
 		return;
 	}