data_chunk Struct Reference

#include <dmaengine.h>

Data Fields
size_t	size
size_t	icg

Detailed Description

Interleaved Transfer Request

A chunk is collection of contiguous bytes to be transfered. The gap(in bytes) between two chunks is called inter-chunk-gap(ICG). ICGs may or maynot change between chunks. A FRAME is the smallest series of contiguous {chunk,icg} pairs, that when repeated an integral number of times, specifies the transfer. A transfer template is specification of a Frame, the number of times it is to be repeated and other per-transfer attributes.

Practically, a client driver would have ready a template for each type of transfer it is going to need during its lifetime and set only 'src_start' and 'dst_start' before submitting the requests.

| Frame-1 | Frame-2 | ~ | Frame-'numf' | |====....==.===...=...|====....==.===...=...| ~ |====....==.===...=...|

== Chunk size ... ICG struct data_chunk - Element of scatter-gather list that makes a frame. : Number of bytes to read from source. size_dst := fn(op, size_src), so doesn't mean much for destination. : Number of bytes to jump after last src/dst address of this chunk and before first src/dst address for next chunk. Ignored for dst(assumed 0), if dst_inc is true and dst_sgl is false. Ignored for src(assumed 0), if src_inc is true and src_sgl is false.

Definition at line 128 of file dmaengine.h.

Field Documentation

size_t icg

Definition at line 130 of file dmaengine.h.

size_t size

Definition at line 129 of file dmaengine.h.

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The documentation for this struct was generated from the following file:

• include/linux/dmaengine.h