diff options
| -rw-r--r-- | Documentation/usb/dma.txt | 18 | ||||
| -rw-r--r-- | drivers/staging/usbip/usbip_common.c | 2 | ||||
| -rw-r--r-- | drivers/usb/core/hcd.c | 3 | ||||
| -rw-r--r-- | include/linux/usb.h | 28 |
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) |