usbcore: Add flag for whether a host controller uses DMA
This patch (as770b) introduces a new field to usb_bus: a flag
indicating whether or not the host controller uses DMA. This serves
to encapsulate the computation. It also means we will have only one
spot to update if the DMA API changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 2102c4d..0cc1420 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1152,7 +1152,7 @@
/* lower level hcd code should use *_dma exclusively,
* unless it uses pio or talks to another transport.
*/
- if (hcd->self.controller->dma_mask) {
+ if (hcd->self.uses_dma) {
if (usb_pipecontrol (urb->pipe)
&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
urb->setup_dma = dma_map_single (
@@ -1585,8 +1585,9 @@
at_root_hub = (urb->dev == hcd->self.root_hub);
urb_unlink (urb);
- /* lower level hcd code should use *_dma exclusively */
- if (hcd->self.controller->dma_mask && !at_root_hub) {
+ /* lower level hcd code should use *_dma exclusively if the
+ * host controller does DMA */
+ if (hcd->self.uses_dma && !at_root_hub) {
if (usb_pipecontrol (urb->pipe)
&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
dma_unmap_single (hcd->self.controller, urb->setup_dma,
@@ -1710,6 +1711,7 @@
hcd->self.release = &hcd_release;
hcd->self.controller = dev;
hcd->self.bus_name = bus_name;
+ hcd->self.uses_dma = (dev->dma_mask != NULL);
init_timer(&hcd->rh_timer);
hcd->rh_timer.function = rh_timer_func;
