mmc: mtk-sd: check for valid optional memory resource
Fabien Parent authored

'top_base' memory region is optional. Check that the resource is valid
before using it. This avoid getting a "invalid resource" error message
printed by the kernel.
Signed-off-by: default avatarFabien Parent <fparent@baylibre.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
b65be635
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.