163ba35ff3
You should use KCFLAGS to pass additional compiler flags from the
command line. Using EXTRA_CFLAGS is wrong.
EXTRA_CFLAGS is supposed to specify flags applied only to the current
Makefile (and now deprecated in favor of ccflags-y).
It is still used in arch/mips/kvm/Makefile (and possibly in external
modules too). Passing EXTRA_CFLAGS from the command line overwrites
it and breaks the build.
I also fixed drivers/gpu/drm/tilcdc/Makefile because commit 816175dd1fd7
("drivers/gpu/drm/tilcdc: Makefile, only -Werror when no -W* in
EXTRA_CFLAGS") was based on the same misunderstanding.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Federico Vaga <federico.vaga@vaga.pv.it>
Link: https://lore.kernel.org/r/20210221152524.197693-1-masahiroy@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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.