d6ac466168
commit c5ee0b3104e0b292d353e63fd31cb8c692645d8c upstream. Serdev sub-system claims all ACPI serial devices that are not already initialised. As a result, no device node is created for serial ports on certain boards such as the Apollo Lake based UP2. This has the unintended consequence of not being able to raise the login prompt via serial connection. Introduce a blacklist to reject ACPI serial devices that should not be claimed by serdev sub-system. Add the peripheral ids for Intel HS UART to the blacklist to bring back serial port on SoCs carrying them. Cc: stable@vger.kernel.org Signed-off-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp> Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Johan Hovold <johan@kernel.org> Cc: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20191219100345.911093-1-punit1.agrawal@toshiba.co.jp 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.