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23aa128bb2
AMD platform device acp_audio_dma can only be created by parent PCI device driver (drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c). Pass struct device of the parent to snd_pcm_lib_preallocate_pages() so dma_alloc_coherent() can use correct dma_ops. Otherwise, it will use default dma_ops which is nommu_dma_ops on x86_64 even when IOMMU is enabled and set to non passthrough mode. Though platform device inherits some dma related fields during its creation in mfd_add_device(), we can't simply pass its struct device to snd_pcm_lib_preallocate_pages() because dma_ops is not among the inherited fields. Even it were, drivers/iommu/amd_iommu.c would ignore it because get_device_id() doesn't handle platform device. This change shouldn't give us any trouble even struct device of the parent becomes null or represents some non PCI device in the future, because get_dma_ops() correctly handles null struct device or uses the default dma_ops if struct device doesn't have it set. Signed-off-by: Yu Zhao <yuzhao@google.com> 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.