1af89dedc8
It is reported that commit31a0fa0019("thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()") causes the ACPI fan driver to fail probing on some systems which turns out to be due to the _FST control method returning an invalid value until _FSL is first evaluated for the given fan. If this happens, the .get_cur_state() cooling device callback returns an error and __thermal_cooling_device_register() fails as uses that callback after commit31a0fa0019. Arguably, _FST should not return an invalid value even if it is evaluated before _FSL, so this may be regarded as a platform firmware issue, but at the same time it is not a good enough reason for failing the cooling device registration where the initial cooling device state is only needed to initialize a thermal debug facility. Accordingly, modify __thermal_cooling_device_register() to avoid calling thermal_debug_cdev_add() instead of returning an error if the initial .get_cur_state() callback invocation fails. Fixes:31a0fa0019("thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()") Closes: https://lore.kernel.org/linux-acpi/20240530153727.843378-1-laura.nao@collabora.com Reported-by: Laura Nao <laura.nao@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Tested-by: Laura Nao <laura.nao@collabora.com>
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 reStructuredText 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.