Commit ab8e8da6 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Jonathan Corbet
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docs: driver-api: usb: avoid using ReST :doc:`foo` markup 



The :doc:`foo` tag is auto-generated via automarkup.py.
So, use the filename at the sources, instead of :doc:`foo`.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/2cd2dc3e6bacde587aeb09a3951594cfb0102014.1623824363.git.mchehab+huawei@kernel.org


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent bbbaf226

Documentation/driver-api/usb/dma.rst

+3 −3
Original line number Original line Diff line number Diff line
@@ -10,7 +10,7 @@ API overview 




The big picture is that USB drivers can continue to ignore most DMA issues,

The big picture is that USB drivers can continue to ignore most DMA issues,

though they still must provide DMA-ready buffers (see

though they still must provide DMA-ready buffers (see

:doc:`/core-api/dma-api-howto`).  That's how they've worked through

Documentation/core-api/dma-api-howto.rst).  That's how they've worked through

the 2.4 (and earlier) kernels, or they can now be DMA-aware.

the 2.4 (and earlier) kernels, or they can now be DMA-aware.





DMA-aware usb drivers:

DMA-aware usb drivers:
@@ -60,7 +60,7 @@ and effects like cache-trashing can impose subtle penalties. 
  force a consistent memory access ordering by using memory barriers.  It's

  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

  not using a streaming DMA mapping, so it's good for small transfers on

  systems where the I/O would otherwise thrash an IOMMU mapping.  (See

  systems where the I/O would otherwise thrash an IOMMU mapping.  (See

  :doc:`/core-api/dma-api-howto` for definitions of "coherent" and

  Documentation/core-api/dma-api-howto.rst for definitions of "coherent" and

  "streaming" DMA mappings.)

  "streaming" DMA mappings.)





  Asking for 1/Nth of a page (as well as asking for N pages) is reasonably

  Asking for 1/Nth of a page (as well as asking for N pages) is reasonably
@@ -91,7 +91,7 @@ Working with existing buffers 
Existing buffers aren't usable for DMA without first being mapped into the

Existing buffers aren't usable for DMA without first being mapped into the

DMA address space of the device.  However, most buffers passed to your

DMA address space of the device.  However, most buffers passed to your

driver can safely be used with such DMA mapping.  (See the first section

driver can safely be used with such DMA mapping.  (See the first section

of :doc:`/core-api/dma-api-howto`, titled "What memory is DMA-able?")

of Documentation/core-api/dma-api-howto.rst, titled "What memory is DMA-able?")





- When you're using scatterlists, you can map everything at once.  On some

- When you're using scatterlists, you can map everything at once.  On some

  systems, this kicks in an IOMMU and turns the scatterlists into single

  systems, this kicks in an IOMMU and turns the scatterlists into single