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authorAlan Stern <stern@rowland.harvard.edu>2010-04-30 16:35:37 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-20 16:21:40 -0400
commit85bcb5ee889e0ebb9154718939e049de265fcdfb (patch)
treedaeec28274c8b68fea502c41af84d45d2681ebc5 /Documentation/usb
parent842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8 (diff)
USB: remove URB_NO_SETUP_DMA_MAP
Now that URB_NO_SETUP_DMA_MAP is no longer in use, this patch (as1376) removes all references to it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/usb')
-rw-r--r--Documentation/usb/dma.txt18
1 files changed, 6 insertions, 12 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.
16 manage dma mappings for existing dma-ready buffers (see below). 16 manage dma mappings for existing dma-ready buffers (see below).
17 17
18- URBs have an additional "transfer_dma" field, as well as a transfer_flags 18- URBs have an additional "transfer_dma" field, as well as a transfer_flags
19 bit saying if it's valid. (Control requests also have "setup_dma" and a 19 bit saying if it's valid. (Control requests also have "setup_dma", but
20 corresponding transfer_flags bit.) 20 drivers must not use it.)
21 21
22- "usbcore" will map those DMA addresses, if a DMA-aware driver didn't do 22- "usbcore" will map this DMA address, if a DMA-aware driver didn't do
23 it first and set URB_NO_TRANSFER_DMA_MAP or URB_NO_SETUP_DMA_MAP. HCDs 23 it first and set URB_NO_TRANSFER_DMA_MAP. HCDs
24 don't manage dma mappings for URBs. 24 don't manage dma mappings for URBs.
25 25
26- There's a new "generic DMA API", parts of which are usable by USB device 26- 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.
53 to use this type of memory ("dma-coherent"), and memory returned from 53 to use this type of memory ("dma-coherent"), and memory returned from
54 kmalloc() will work just fine. 54 kmalloc() will work just fine.
55 55
56 For control transfers you can use the buffer primitives or not for each
57 of the transfer buffer and setup buffer independently. Set the flag bits
58 URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP to indicate which
59 buffers you have prepared. For non-control transfers URB_NO_SETUP_DMA_MAP
60 is ignored.
61
62 The memory buffer returned is "dma-coherent"; sometimes you might need to 56 The memory buffer returned is "dma-coherent"; sometimes you might need to
63 force a consistent memory access ordering by using memory barriers. It's 57 force a consistent memory access ordering by using memory barriers. It's
64 not using a streaming DMA mapping, so it's good for small transfers on 58 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?")
130 void usb_buffer_unmap (struct urb *urb); 124 void usb_buffer_unmap (struct urb *urb);
131 125
132 The calls manage urb->transfer_dma for you, and set URB_NO_TRANSFER_DMA_MAP 126 The calls manage urb->transfer_dma for you, and set URB_NO_TRANSFER_DMA_MAP
133 so that usbcore won't map or unmap the buffer. The same goes for 127 so that usbcore won't map or unmap the buffer. They cannot be used for
134 urb->setup_dma and URB_NO_SETUP_DMA_MAP for control requests. 128 setup_packet buffers in control requests.
135 129
136Note that several of those interfaces are currently commented out, since 130Note that several of those interfaces are currently commented out, since
137they don't have current users. See the source code. Other than the dmasync 131they don't have current users. See the source code. Other than the dmasync