sata_mv: mv_fill_sg fixes v2

Fix mv_fill_sg() to zero out the reserved word (required for ATAPI),
and to include a memory barrier.  This may also help with problems
reported by Jens on the PPC platform.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 181f02127410..9c8ea2c1116d 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1364,12 +1364,13 @@ static void mv_fill_sg(struct ata_queued_cmd *qc)
                         u32 offset = addr & 0xffff;
                         u32 len = sg_len;
 
-                        if ((offset + sg_len > 0x10000))
+                        if (offset + len > 0x10000)
                                 len = 0x10000 - offset;
 
                         mv_sg->addr = cpu_to_le32(addr & 0xffffffff);
                         mv_sg->addr_hi = cpu_to_le32((addr >> 16) >> 16);
                         mv_sg->flags_size = cpu_to_le32(len & 0xffff);
+                        mv_sg->reserved = 0;
 
                         sg_len -= len;
                         addr += len;
@@ -1381,6 +1382,7 @@ static void mv_fill_sg(struct ata_queued_cmd *qc)
 
         if (likely(last_sg))
                 last_sg->flags_size |= cpu_to_le32(EPRD_FLAG_END_OF_TBL);
+        mb(); /* ensure data structure is visible to the chipset */
 }
 
 static void mv_crqb_pack_cmd(__le16 *cmdw, u8 data, u8 addr, unsigned last)