diff options
Diffstat (limited to 'include/linux/usb.h')
| -rw-r--r-- | include/linux/usb.h | 28 |
1 files changed, 11 insertions, 17 deletions
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) |