[PATCH #upstream-fixes] sata_nv: disable ADMA mode by default

[Tejun Heo <htejun@gmail.com>]

There still are remaining issues with ADMA support.  Disable it by
default and warn when enabling.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
Jeff, please hold off till Robert acks.  Robert, what do you think?

 drivers/ata/sata_nv.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index ed5dc7c..27a0e34 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -639,7 +639,7 @@ MODULE_LICENSE("GPL");
 MODULE_DEVICE_TABLE(pci, nv_pci_tbl);
 MODULE_VERSION(DRV_VERSION);
 
-static int adma_enabled = 1;
+static int adma_enabled = 0;
 static int swncq_enabled;
 
 static void nv_adma_register_mode(struct ata_port *ap)
@@ -2396,6 +2396,9 @@ static int nv_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	/* determine type and allocate host */
 	if (type == CK804 && adma_enabled) {
 		dev_printk(KERN_NOTICE, &pdev->dev, "Using ADMA mode\n");
+		dev_printk(KERN_WARNING, &pdev->dev,
+			   "WARNING: There are known problems with ADMA mode "
+			   "which may lead to timeouts and/or system lock ups.\n");
 		type = ADMA;
 	}