SVR5

dma_swstart(D3)

dma_swstart -- initiate a DMA operation via software request

Synopsis

   #include <sys/types.h>
   #include <sys/dma.h>
   #include <sys/ddi.h>
   
   void dma_swstart(struct dma_cb *dmacbptr, int chan, uchar_t mode);

Description

dma_swstart initiates a DMA operation previously programmed by dma_swsetup(D3) on the ISA, EISA, or MCA DMA channel.

Arguments

dmacbptr: Pointer to a DMA command block that specifies the DMA operation.
chan: Channel over which the operation is to take place.
mode: Specifies whether the caller should sleep waiting for the operation to complete.

Return values

None.

Usage

If mode is set to DMA_NOSLEEP, then dma_swstart simply starts the operation but does not wait for the operation to complete and instead returns to the caller immediately. If mode is set to DMA_SLEEP, then dma_swstart starts the operation and then waits for the operation to complete, and returns to the caller after the operation has finished.

The operation being initiated must have already been programmed on the specified channel by dma_swsetup.

Context and synchronization

If mode is set to DMA_NOSLEEP, non-blockable, initialization, or interrupt context.

If mode is set to DMA_SLEEP, user context.

Hardware applicability

PC-AT compatible platforms with ISA, EISA, or MCA buses

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp

Future directions

This interface is expected to be replaced or modified in a future release.

References

dma_stop(D3), dma_swsetup(D3), dma_cb(D4)

``DMA'' in HDK Technical Reference