Add a mutex lock to prevent race between controller ops initiated by the bus subsystem and the controller registration/unregistration. Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com> Link: https://lore.kernel.org/r/20231017160505.10640-3-abhijit.gangurde@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>