187fade88c
If mapping the CvP BAR fails, we still can configure the FPGA via PCI config space access. In this case the iomap pointer is NULL. On x86_64, passing NULL address to pci_iounmap() generates "Bad IO access at port 0x0" output with stack call trace. Fix it. Signed-off-by: Anatolij Gustschin <agust@denx.de> Acked-by: Alan Tull <atull@kernel.org> 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.
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.