From 3acec69a94eaaf3d7ebb043e1db45cc26f58a847 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Fri, 8 Mar 2024 12:32:03 +0000 Subject: 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 Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki --- kernel/power/energy_model.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel') diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index b686ac0345bd..9e1c9aa399ea 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -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; -- cgit v1.2.3