9c25af2502
The earlier commit to fix runtime PM in case i915 init fails, introduces a possibility to hit a page fault. snd_hdac_ext_bus_device_exit() is designed to be called from dev.release(). Calling it outside device reference counting, is not safe and may lead to calling the device_exit() function twice. Additionally, as part of ext_bus_device_init(), the device is also registered with snd_hdac_device_register(). Thus before calling device_exit(), the device must be removed from device hierarchy first. Fix the issue by rolling back init actions by calling hdac_device_unregister() and then releasing device with put_device(). This matches with existing code in hdac-ext module. To complete the fix, add handling for the case where hda_codec_load_module() returns -ENODEV, and clean up the hdac_ext resources also in this case. In future work, hdac-ext interface should be extended to allow clients more flexibility to handle the life-cycle of individual devices, beyond just the current snd_hdac_ext_bus_device_remove(), which removes all devices. BugLink: https://github.com/thesofproject/linux/issues/2646 Reported-by: Jaroslav Kysela <perex@perex.cz> Fixes: 6c63c954e1c5 ("ASoC: SOF: fix a runtime pm issue in SOF when HDMI codec doesn't work") Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Reviewed-by: Libin Yang <libin.yang@intel.com> Reviewed-by: Bard Liao <bard.liao@intel.com> Link: https://lore.kernel.org/r/20210113150715.3992635-1-kai.vehmanen@linux.intel.com Signed-off-by: Mark Brown <broonie@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.