e43ab59fb1
[ Upstream commit 2c63bea714780f8e1fc9cb7bc10deda26fada25b ] In case system has multiple HDA controllers, it can happen that same HDA codec driver is used for codecs of multiple controllers. In this case, SOF may fail to probe the HDA driver and SOF initialization fails. SOF HDA code currently relies that a call to request_module() will also run device matching logic to attach driver to the codec instance. However if driver for another HDA controller was already loaded and it already loaded the HDA codec driver, this breaks current logic in SOF. In this case the request_module() SOF does becomes a no-op and HDA Codec driver is not attached to the codec instance sitting on the HDA bus SOF is controlling. Typical scenario would be a system with both external and internal GPUs, with driver of the external GPU loaded first. Fix this by adding similar logic as is used in legacy HDA driver where an explicit device_attach() call is done after request_module(). Also add logic to propagate errors reported by device_attach() back to caller. This also works in the case where drivers are not built as modules. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20200110235751.3404-8-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.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.