pata_platform: don't use generic ata_port_start

I have a system where I have a simple IDE controller that sits on a
local bus without bus master dma capability, and thus no dma_mapping
ops defined for the device/bus.

pata_platform works great for me, with the exception of using the generic
ata_port_start which tries to do a dmam_alloc_coherent.

Looks like it doesn't need to allocate a prd table at all, so replace it
with a dummy function instead.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index a0a650c7f272..1f6384895a4f 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -48,6 +48,8 @@ static int pata_platform_set_mode(struct ata_port *ap, struct ata_device **unuse
         return 0;
 }
 
+static int ata_dummy_ret0(struct ata_port *ap)  { return 0; }
+
 static struct scsi_host_template pata_platform_sht = {
         .module                 = THIS_MODULE,
         .name                   = DRV_NAME,
@@ -91,7 +93,7 @@ static struct ata_port_operations pata_platform_port_ops = {
         .irq_on                 = ata_irq_on,
         .irq_ack                = ata_irq_ack,
 
-        .port_start             = ata_port_start,
+        .port_start             = ata_dummy_ret0,
 };
 
 static void pata_platform_setup_port(struct ata_ioports *ioaddr,