sata_dwc_460ex: support hardreset

The hardreset operation is currently not supported. This causes
sometime the SATA driver does cause kernel crash because of
none-determined state.a This patch will fix the issue.

Signed-off-by: Thang Q. Nguyen <tqnguyen@apm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 69f7cde49c6b..ae13ef1945ba 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -1581,10 +1581,31 @@ static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
 
 static void sata_dwc_error_handler(struct ata_port *ap)
 {
-        ap->link.flags |= ATA_LFLAG_NO_HRST;
         ata_sff_error_handler(ap);
 }
 
+int sata_dwc_hardreset(struct ata_link *link, unsigned int *class,
+                        unsigned long deadline)
+{
+        struct sata_dwc_device *hsdev = HSDEV_FROM_AP(link->ap);
+        int ret;
+
+        ret = sata_sff_hardreset(link, class, deadline);
+
+        sata_dwc_enable_interrupts(hsdev);
+
+        /* Reconfigure the DMA control register */
+        out_le32(&hsdev->sata_dwc_regs->dmacr,
+                 SATA_DWC_DMACR_TXRXCH_CLEAR);
+
+        /* Reconfigure the DMA Burst Transaction Size register */
+        out_le32(&hsdev->sata_dwc_regs->dbtsr,
+                 SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
+                 SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT));
+
+        return ret;
+}
+
 /*
  * scsi mid-layer and libata interface structures
  */
@@ -1604,6 +1625,7 @@ static struct ata_port_operations sata_dwc_ops = {
         .inherits               = &ata_sff_port_ops,
 
         .error_handler          = sata_dwc_error_handler,
+        .hardreset              = sata_dwc_hardreset,
 
         .qc_prep                = sata_dwc_qc_prep,
         .qc_issue               = sata_dwc_qc_issue,