diff options
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man9/bus_dma.9 | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/share/man/man9/bus_dma.9 b/share/man/man9/bus_dma.9 index 467dd07..7445d2e 100644 --- a/share/man/man9/bus_dma.9 +++ b/share/man/man9/bus_dma.9 @@ -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 |