sata_mv ncq Restrict max sectors to 8-bits on GenII NCQ

The GenII chips have only 8-bits for the sector_count field when performing NCQ.
Add a dev_config method to restrict this when necessary, taking care not to
override any other restriction already in place (likely none, but someday.. ?).

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 207c400c64df..d15caf32045e 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -449,6 +449,7 @@ static void mv_error_handler(struct ata_port *ap);
 static void mv_post_int_cmd(struct ata_queued_cmd *qc);
 static void mv_eh_freeze(struct ata_port *ap);
 static void mv_eh_thaw(struct ata_port *ap);
+static void mv6_dev_config(struct ata_device *dev);
 static int mv_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 
 static void mv5_phy_errata(struct mv_host_priv *hpriv, void __iomem *mmio,
@@ -541,6 +542,7 @@ static const struct ata_port_operations mv5_ops = {
 };
 
 static const struct ata_port_operations mv6_ops = {
+        .dev_config             = mv6_dev_config,
         .tf_load                = ata_tf_load,
         .tf_read                = ata_tf_read,
         .check_status           = ata_check_status,
@@ -1054,6 +1056,17 @@ static int mv_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val)
                 return -EINVAL;
 }
 
+static void mv6_dev_config(struct ata_device *adev)
+{
+        /*
+         * We don't have hob_nsect when doing NCQ commands on Gen-II.
+         * See mv_qc_prep() for more info.
+         */
+        if (adev->flags & ATA_DFLAG_NCQ)
+                if (adev->max_sectors > ATA_MAX_SECTORS)
+                        adev->max_sectors = ATA_MAX_SECTORS;
+}
+
 static void mv_edma_cfg(struct mv_port_priv *pp, struct mv_host_priv *hpriv,
                         void __iomem *port_mmio, int want_ncq)
 {