079c42a0ed
Make set_performance_state() callback optional in order to remove the need from power domain drivers to implement a dummy callback. If callback isn't implemented by a GENPD driver, then the performance state is passed to the parent domain. Tested-by: Peter Geis <pgwipeout@gmail.com> Tested-by: Nicolas Chauvet <kwizart@gmail.com> Tested-by: Matt Merhar <mattmerhar@protonmail.com> [tested on NVIDIA Tegra20/30/124 SoCs] Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>