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update examples to use the correct terms that was never updated when the

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earlier descriptions were gone over...

MFC after:	3 days
This commit is contained in:
jmg 2006-02-28 19:58:57 +00:00
parent 02a7a75f38
commit 7f0fea077c
1 changed files with 3 additions and 3 deletions
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6
share/man/man9/bus_dma.9
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@ -676,17 +676,17 @@ For example, the CPU might be used to setup the contents of a buffer
that is to be DMA'ed into a device.
To ensure that the data are visible via the device's mapping of that
memory, the buffer must be loaded and a dma sync operation of
.Dv BUS_DMASYNC_PREREAD
.Dv BUS_DMASYNC_PREWRITE
must be performed.
Additional sync operations must be performed after every CPU write
to this memory if additional DMA reads are to be performed.
Conversely, for the DMA write case, the buffer must be loaded,
and a dma sync operation of
.Dv BUS_DMASYNC_PREWRITE
.Dv BUS_DMASYNC_PREREAD
must be performed.
The CPU will only be able to see the results of this DMA write
once the DMA has completed and a
.Dv BUS_DMASYNC_POSTWRITE
.Dv BUS_DMASYNC_POSTREAD
operation has been performed.
.Pp
If DMA read and write operations are not preceded and followed by the