On 2020-06-22 5:42 PM, Pierre-Louis Bossart wrote:
The mainline code currently prevents modules from being removed. The BE dailink .init() function calls devm_gpiod_get() using the codec component device as argument. When the machine driver is removed, the references to the gpiod are not released, and it's not possible to remove the codec driver module - which is the only entity which could free the gpiod. This conceptual deadlock can be avoided by invoking gpiod_get() in the .init() callback, and calling gpiod_put() in the exit() callback. Tested on SAMUS Chromebook with SOF driver.
As /intel/haswell is the go-to driver for BDW platforms, please test and confirm with legacy driver first. SOF is optional and thus non-blocking.
Czarek
