4 files changed, 19 insertions, 32 deletions

diff --git a/Documentation/usb/dma.txt b/Documentation/usb/dma.txt
index a37e59cf2786..84ef865237db 100644
--- a/Documentation/usb/dma.txt
+++ b/Documentation/usb/dma.txt
@@ -16,11 +16,11 @@ OR:  they can now be DMA-aware.
   manage dma mappings for existing dma-ready buffers (see below).
 
 - URBs have an additional "transfer_dma" field, as well as a transfer_flags
-  bit saying if it's valid.  (Control requests also have "setup_dma" and a
-  corresponding transfer_flags bit.)
+  bit saying if it's valid.  (Control requests also have "setup_dma", but
+  drivers must not use it.)
 
-- "usbcore" will map those DMA addresses, if a DMA-aware driver didn't do
-  it first and set URB_NO_TRANSFER_DMA_MAP or URB_NO_SETUP_DMA_MAP.  HCDs
+- "usbcore" will map this DMA address, if a DMA-aware driver didn't do
+  it first and set URB_NO_TRANSFER_DMA_MAP.  HCDs
   don't manage dma mappings for URBs.
 
 - There's a new "generic DMA API", parts of which are usable by USB device
@@ -53,12 +53,6 @@ and effects like cache-trashing can impose subtle penalties.
   to use this type of memory ("dma-coherent"), and memory returned from
   kmalloc() will work just fine.
 
-  For control transfers you can use the buffer primitives or not for each
-  of the transfer buffer and setup buffer independently.  Set the flag bits
-  URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP to indicate which
-  buffers you have prepared.  For non-control transfers URB_NO_SETUP_DMA_MAP
-  is ignored.
-
   The memory buffer returned is "dma-coherent"; sometimes you might need to
   force a consistent memory access ordering by using memory barriers.  It's
   not using a streaming DMA mapping, so it's good for small transfers on
@@ -130,8 +124,8 @@ of Documentation/PCI/PCI-DMA-mapping.txt, titled "What memory is DMA-able?")
         void usb_buffer_unmap (struct urb *urb);
 
   The calls manage urb->transfer_dma for you, and set URB_NO_TRANSFER_DMA_MAP
-  so that usbcore won't map or unmap the buffer.  The same goes for
-  urb->setup_dma and URB_NO_SETUP_DMA_MAP for control requests.
+  so that usbcore won't map or unmap the buffer.  They cannot be used for
+  setup_packet buffers in control requests.
 
 Note that several of those interfaces are currently commented out, since
 they don't have current users.  See the source code.  Other than the dmasync
diff --git a/drivers/staging/usbip/usbip_common.c b/drivers/staging/usbip/usbip_common.c
index e3fa4216c1cd..52408164036f 100644
--- a/drivers/staging/usbip/usbip_common.c
+++ b/drivers/staging/usbip/usbip_common.c
@@ -562,7 +562,7 @@ EXPORT_SYMBOL_GPL(sockfd_to_socket);
 /* there may be more cases to tweak the flags. */
 static unsigned int tweak_transfer_flags(unsigned int flags)
 {
-        flags &= ~(URB_NO_TRANSFER_DMA_MAP|URB_NO_SETUP_DMA_MAP);
+        flags &= ~URB_NO_TRANSFER_DMA_MAP;
         return flags;
 }
 
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 3aaee2811f01..0abc5c537f39 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1316,8 +1316,7 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
          * or uses the provided scatter gather list for bulk.
          */
 
-        if (usb_endpoint_xfer_control(&urb->ep->desc)
-            && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
+        if (usb_endpoint_xfer_control(&urb->ep->desc)) {
                 if (hcd->self.uses_dma) {
                         urb->setup_dma = dma_map_single(
                                         hcd->self.controller,
diff --git a/include/linux/usb.h b/include/linux/usb.h
index a748815ee629..1eb4762d9ea8 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -953,7 +953,6 @@ extern int usb_disabled(void);
 #define URB_ISO_ASAP            0x0002  /* iso-only, urb->start_frame
                                          * ignored */
 #define URB_NO_TRANSFER_DMA_MAP 0x0004  /* urb->transfer_dma valid on submit */
-#define URB_NO_SETUP_DMA_MAP    0x0008  /* urb->setup_dma valid on submit */
 #define URB_NO_FSBR             0x0020  /* UHCI-specific */
 #define URB_ZERO_PACKET         0x0040  /* Finish bulk OUT with short packet */
 #define URB_NO_INTERRUPT        0x0080  /* HINT: no non-error interrupt
@@ -1049,12 +1048,8 @@ typedef void (*usb_complete_t)(struct urb *);
  * @setup_packet: Only used for control transfers, this points to eight bytes
  *      of setup data.  Control transfers always start by sending this data
  *      to the device.  Then transfer_buffer is read or written, if needed.
- * @setup_dma: For control transfers with URB_NO_SETUP_DMA_MAP set, the
- *      device driver has provided this DMA address for the setup packet.
- *      The host controller driver should use this in preference to
- *      setup_packet, but the HCD may chose to ignore the address if it must
- *      copy the setup packet into internal structures.  Therefore, setup_packet
- *      must always point to a valid buffer.
+ * @setup_dma: DMA pointer for the setup packet.  The caller must not use
+ *      this field; setup_packet must point to a valid buffer.
  * @start_frame: Returns the initial frame for isochronous transfers.
  * @number_of_packets: Lists the number of ISO transfer buffers.
  * @interval: Specifies the polling interval for interrupt or isochronous
@@ -1086,13 +1081,14 @@ typedef void (*usb_complete_t)(struct urb *);
  * bounce buffer or talking to an IOMMU),
  * although they're cheap on commodity x86 and ppc hardware.
  *
- * Alternatively, drivers may pass the URB_NO_xxx_DMA_MAP transfer flags,
- * which tell the host controller driver that no such mapping is needed since
+ * Alternatively, drivers may pass the URB_NO_TRANSFER_DMA_MAP transfer flag,
+ * which tells the host controller driver that no such mapping is needed for
+ * the transfer_buffer since
  * the device driver is DMA-aware.  For example, a device driver might
  * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map().
- * When these transfer flags are provided, host controller drivers will
- * attempt to use the dma addresses found in the transfer_dma and/or
- * setup_dma fields rather than determining a dma address themselves.
+ * When this transfer flag is provided, host controller drivers will
+ * attempt to use the dma address found in the transfer_dma
+ * field rather than determining a dma address themselves.
  *
  * Note that transfer_buffer must still be set if the controller
  * does not support DMA (as indicated by bus.uses_dma) and when talking
@@ -1115,11 +1111,9 @@ typedef void (*usb_complete_t)(struct urb *);
  * should always terminate with a short packet, even if it means adding an
  * extra zero length packet.
  *
- * Control URBs must provide a setup_packet.  The setup_packet and
- * transfer_buffer may each be mapped for DMA or not, independently of
- * the other.  The transfer_flags bits URB_NO_TRANSFER_DMA_MAP and
- * URB_NO_SETUP_DMA_MAP indicate which buffers have already been mapped.
- * URB_NO_SETUP_DMA_MAP is ignored for non-control URBs.
+ * Control URBs must provide a valid pointer in the setup_packet field.
+ * Unlike the transfer_buffer, the setup_packet may not be mapped for DMA
+ * beforehand.
  *
  * Interrupt URBs must provide an interval, saying how often (in milliseconds
  * or, for highspeed devices, 125 microsecond units)