e534b82f24
Currently, when use standard tuning, driver default disable DMA just before send tuning command. But on i.MX8 usdhc, this is not enough. Need also clear DMA_SEL. If not, once the DMA_SEL select AMDA2 before, even dma already disabled, when send tuning command, usdhc will still prefetch the ADMA script from wrong DMA address, then we will see IOMMU report some error which show lack of TLB mapping. Signed-off-by: Haibo Chen <haibo.chen@nxp.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/1582100757-20683-7-git-send-email-haibo.chen@nxp.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.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.