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ab650ef6d5
If the DMA device supports per channel coherency configuration (a channel can be configured to have coherent or not coherent view) then a single device (the DMA controller's device) can not be used for dma_api for all channels as channels can have different coherency. Introduce custom_dma_mapping flag for the dma_chan and a new helper to get the device pointer to be used for dma_api for the given channel. Client drivers should be updated to be able to support per channel coherency by: - dma_map_single(chan->device->dev, ptr, size, DMA_TO_DEVICE); + struct device *dma_dev = dmaengine_get_dma_device(chan); + + dma_map_single(dma_dev, ptr, size, DMA_TO_DEVICE); Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Link: https://lore.kernel.org/r/20201208090440.31792-9-peter.ujfalusi@ti.com Signed-off-by: Vinod Koul <vkoul@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.