Messages in this thread Patch in this message | | | From | Lukasz Luba <> | Subject | [PATCH 07/17] PM: EM: Check if the get_cost() callback is present in em_compute_costs() | Date | Tue, 14 Mar 2023 10:33:47 +0000 |
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The em_compute_cost() is going to be re-used in runtime modified EM code path. Thus, make sure that this common code is safe and won't try to use the NULL pointer. The former em_compute_cost() didn't have to care about runtime modification code path. The upcoming changes introduce such option, but with different callback. Those two paths which use get_cost() (during first EM registration) or update_power() (during runtime modification) need to be safely handled in em_compute_costs().
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- kernel/power/energy_model.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 3b778743ba89..230310709e2a 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -122,7 +122,7 @@ static int em_compute_costs(struct device *dev, struct em_perf_state *table, for (i = nr_states - 1; i >= 0; i--) { unsigned long power_res, cost; - if (flags & EM_PERF_DOMAIN_ARTIFICIAL) { + if (flags & EM_PERF_DOMAIN_ARTIFICIAL && cb->get_cost) { ret = cb->get_cost(dev, table[i].frequency, &cost); if (ret || !cost || cost > EM_MAX_POWER) { dev_err(dev, "EM: invalid cost %lu %d\n", -- 2.17.1
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