47ec7f09bc
The cookie tracking in dmaengine expects all submissions completed in order. Some DMA devices like Intel DSA can complete submissions out of order, especially if configured with a work queue sharing multiple DMA engines. Add a status DMA_OUT_OF_ORDER that tx_status can be returned for those DMA devices. The user should use callbacks to track the completion rather than the DMA cookie. This would address the issue of dmatest complaining that descriptors are "busy" when the cookie count goes backwards due to out of order completion. Add DMA_COMPLETION_NO_ORDER DMA capability to allow the driver to flag the device's ability to complete operations out of order. Reported-by: Swathi Kovvuri <swathi.kovvuri@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Swathi Kovvuri <swathi.kovvuri@intel.com> Link: https://lore.kernel.org/r/158939557151.20335.12404113976045569870.stgit@djiang5-desk3.ch.intel.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.