cce1396936
We use 2-stage DMA mode to support Spreadtrum audio compress offload, which means we use one DMA source channel to transfer data from IRAM buffer to the DSP fifo to do decoding/encoding, once IRAM buffer is empty by transferring done, another DMA destination channel will be triggered automatically to start to transfer data from DDR buffer to the IRAM buffer. This can reduce the AP subsystem wakeup times to save power. Co-developed-by: Yintang Ren <yintang.ren@unisoc.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.