Commit 3acec69a authored Mar 08, 2024 by Lukasz Luba Committed by Rafael J. Wysocki Mar 13, 2024

PM: EM: Force device drivers to provide power in uW



The EM only supports power in uW. Make sure that it is not possible to
register some downstream driver which doesn't provide power in uW.
The only exception is artificial EM, but that EM is ignored by the rest of
kernel frameworks (thermal, powercap, etc).

Reported-by: PoShao Chen <poshao.chen@mediatek.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 07abb19a

kernel/power/energy_model.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -612,6 +612,17 @@ int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states,
		else if (cb->get_cost)
		flags \|= EM_PERF_DOMAIN_ARTIFICIAL;

		/*
		* EM only supports uW (exception is artificial EM).
		* Therefore, check and force the drivers to provide
		* power in uW.
		*/
		if (!microwatts && !(flags & EM_PERF_DOMAIN_ARTIFICIAL)) {
		dev_err(dev, "EM: only supports uW power values\n");
		ret = -EINVAL;
		goto unlock;
		}

		ret = em_create_pd(dev, nr_states, cb, cpus, flags);
		if (ret)
		goto unlock;