5aaf9efffc
Add a basic test for the mixer control interface. For every control on every sound card in the system it checks that it can read and write the default value where the control supports that and for writeable controls attempts to write all valid values, restoring the default values after each test to minimise disruption for users. There are quite a few areas for improvement - currently no coverage of the generation of notifications, several of the control types don't have any coverage for the values and we don't have any testing of error handling when we attempt to write out of range values - but this provides some basic coverage. This is added as a kselftest since unlike other ALSA test programs it does not require either physical setup of the device or interactive monitoring by users and kselftest is one of the test suites that is frequently run by people doing general automated testing so should increase coverage. It is written in terms of alsa-lib since tinyalsa is not generally packaged for distributions which makes things harder for general users interested in kselftest as a whole but it will be a barrier to people with Android. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/20211210185410.740009-2-broonie@kernel.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
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.