ahci: disable 64bit dma on sb600
SB600 claims it can do 64bit DMA but it can't. Disable it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index e00e1b9..bb94047 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -170,6 +170,7 @@
AHCI_FLAG_IGN_IRQ_IF_ERR = (1 << 25), /* ignore IRQ_IF_ERR */
AHCI_FLAG_HONOR_PI = (1 << 26), /* honor PORTS_IMPL */
AHCI_FLAG_IGN_SERR_INTERNAL = (1 << 27), /* ignore SERR_INTERNAL */
+ AHCI_FLAG_32BIT_ONLY = (1 << 28), /* force 32bit */
AHCI_FLAG_COMMON = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
@@ -354,7 +355,8 @@
/* board_ahci_sb600 */
{
.flags = AHCI_FLAG_COMMON |
- AHCI_FLAG_IGN_SERR_INTERNAL,
+ AHCI_FLAG_IGN_SERR_INTERNAL |
+ AHCI_FLAG_32BIT_ONLY,
.pio_mask = 0x1f, /* pio0-4 */
.udma_mask = 0x7f, /* udma0-6 ; FIXME */
.port_ops = &ahci_ops,
@@ -492,6 +494,13 @@
hpriv->saved_cap = cap = readl(mmio + HOST_CAP);
hpriv->saved_port_map = port_map = readl(mmio + HOST_PORTS_IMPL);
+ /* some chips lie about 64bit support */
+ if ((cap & HOST_CAP_64) && (pi->flags & AHCI_FLAG_32BIT_ONLY)) {
+ dev_printk(KERN_INFO, &pdev->dev,
+ "controller can't do 64bit DMA, forcing 32bit\n");
+ cap &= ~HOST_CAP_64;
+ }
+
/* fixup zero port_map */
if (!port_map) {
port_map = (1 << ahci_nr_ports(hpriv->cap)) - 1;