fb16a38351
The memory access to the pages allocated with SNDRV_DMA_TYPE_CONTINUOUS are basically non-coherent, and it becomes a problem when a process accesses via mmap. For the more consistent access, use the device coherent memory, just by replacing the call pattern in the allocator helpers. The only point we need to be careful for is the device object passed there; since bcm2835-audio driver creates fake devices and each card is created on top of that, we need to pass its parent device as the real device object. Signed-off-by: Takashi Iwai <tiwai@suse.de> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.