[PATCH] sata_fsl: Fix the command description of FSL SATA controller

[Kumar Gala]

From: Dave Liu <daveliu at freescale.com>

The bit 11 of command description is reserved bit in Freescale
SATA controller and needs to be set to '1'.  This is needed to
make sure the last write from the controller to the buffer
descriptor is seen before an interrupt is raised.

Signed-off-by: Dave Liu <daveliu at freescale.com>
Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
---

Jeff, please pick this up as a bug fix for 2.6.30

 drivers/ata/sata_fsl.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index 5edd654..36b8629 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -205,6 +205,7 @@ struct cmdhdr_tbl_entry {
  * Description information bitdefs
  */
 enum {
+	CMD_DESC_RES = (1 << 11),
 	VENDOR_SPECIFIC_BIST = (1 << 10),
 	CMD_DESC_SNOOP_ENABLE = (1 << 9),
 	FPDMA_QUEUED_CMD = (1 << 8),
@@ -388,7 +389,7 @@ static void sata_fsl_qc_prep(struct ata_queued_cmd *qc)
 	void __iomem *hcr_base = host_priv->hcr_base;
 	unsigned int tag = sata_fsl_tag(qc->tag, hcr_base);
 	struct command_desc *cd;
-	u32 desc_info = CMD_DESC_SNOOP_ENABLE;
+	u32 desc_info = CMD_DESC_RES | CMD_DESC_SNOOP_ENABLE;
 	u32 num_prde = 0;
 	u32 ttl_dwords = 0;
 	dma_addr_t cd_paddr;
@@ -841,7 +842,7 @@ issue_srst:

 	/* device reset/SRST is a control register update FIS, uses tag0 */
 	sata_fsl_setup_cmd_hdr_entry(pp, 0,
-				     SRST_CMD | CMD_DESC_SNOOP_ENABLE, 0, 0, 5);
+		SRST_CMD | CMD_DESC_RES | CMD_DESC_SNOOP_ENABLE, 0, 0, 5);

 	tf.ctl |= ATA_SRST;	/* setup SRST bit in taskfile control reg */
 	ata_tf_to_fis(&tf, pmp, 0, cfis);
@@ -887,7 +888,8 @@ issue_srst:
 	 * using ATA signature D2H register FIS to the host controller.
 	 */

-	sata_fsl_setup_cmd_hdr_entry(pp, 0, CMD_DESC_SNOOP_ENABLE, 0, 0, 5);
+	sata_fsl_setup_cmd_hdr_entry(pp, 0, CMD_DESC_RES | CMD_DESC_SNOOP_ENABLE,
+				      0, 0, 5);

 	tf.ctl &= ~ATA_SRST;	/* 2nd H2D Ctl. register FIS */
 	ata_tf_to_fis(&tf, pmp, 0, cfis);
-- 
1.6.0.6