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>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 4709033f8fa7..09661759621f 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -269,6 +269,7 @@ struct usb_bus {
         struct device *controller;      /* host/master side hardware */
         int busnum;                     /* Bus number (in order of reg) */
         char *bus_name;                 /* stable id (PCI slot_name etc) */
+        u8 uses_dma;                    /* Does the host controller use DMA? */
         u8 otg_port;                    /* 0, or number of OTG/HNP port */
         unsigned is_b_host:1;           /* true during some HNP roleswitches */
         unsigned b_hnp_enable:1;        /* OTG: did A-Host enable HNP? */