mirror of https://gitee.com/openkylin/linux.git
a7e335deed
The Spreadtrum Audio compress offload mode will use 2-stage DMA transfer to save power. That means we can request 2 dma channels, one for source channel, and another one for destination channel. Once the source channel's transaction is done, it will trigger the destination channel's transaction automatically by hardware signal. In this case, the source channel will transfer data from IRAM buffer to the DSP fifo to decoding/encoding, once IRAM buffer is empty by transferring done, the destination channel will start to transfer data from DDR buffer to IRAM buffer. Since the destination channel will use link-list mode to fill the IRAM data, and IRAM buffer is allocated by 32K, and DDR buffer is larger to 2M, that means we need lots of link-list nodes to do a cyclic transfer, instead wasting lots of link-list memory, we can use wrap address support to reduce link-list node number, which means when the transfer address reaches the wrap address, the transfer address will jump to the wrap_to address specified by wrap_to register, and only 2 link-list nodes can do a cyclic transfer to transfer data from DDR to IRAM. Thus this patch adds wrap address to support this case. [Baolin Wang changes the commit message] Signed-off-by: Eric Long <eric.long@unisoc.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Link: https://lore.kernel.org/r/85a5484bc1f3dd53ce6f92700ad8b35f30a0b096.1571812029.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org> |
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| fs | ||
| include | ||
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| ipc | ||
| kernel | ||
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| samples | ||
| scripts | ||
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| sound | ||
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| .cocciconfig | ||
| .get_maintainer.ignore | ||
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| .gitignore | ||
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| README | ||
README
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.