PM / Domains: Rework default device stop governor function, v2

The existing default device stop governor function for PM domains,
default_stop_ok(), is supposed to check whether or not the device's
PM QoS latency constraint will be violated if the device is stopped
by pm_genpd_runtime_suspend().  However, the computations carried out
by it don't reflect the definition of the PM QoS latency constrait in
Documentation/ABI/testing/sysfs-devices-power.

Make default_stop_ok() follow the definition of the PM QoS latency
constrait.  In particular, make it take the device's start and stop
latencies correctly.

Add a new field, effective_constraint_ns, to struct gpd_timing_data
and use it to store the difference between the device's PM QoS
constraint and its resume latency for use by the device's parent
(the effective_constraint_ns values for the children are used for
computing the parent's one along with its PM QoS constraint).

Remove the break_even_ns field from struct gpd_timing_data, because
it's not used any more.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 91f8286106ea..9c25219458c2 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -93,7 +93,7 @@ struct gpd_timing_data {
         s64 start_latency_ns;
         s64 save_state_latency_ns;
         s64 restore_state_latency_ns;
-        s64 break_even_ns;
+        s64 effective_constraint_ns;
 };
 
 struct generic_pm_domain_data {