PM: domains: enable domain idle state accounting

To enable better debug of PM domains, keep a track of successful
and failing attempts to enter each domain idle state.

This statistics are exported in debugfs when reading the
idle_states node associated with each PM domain.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index bc42439..859cdb2 100644 (file)
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -591,11 +591,14 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
                return -EBUSY;
 
        ret = _genpd_power_off(genpd, true);
-       if (ret)
+       if (ret) {
+               genpd->states[genpd->state_idx].rejected++;
                return ret;
+       }
 
        genpd->status = GENPD_STATE_OFF;
        genpd_update_accounting(genpd);
+       genpd->states[genpd->state_idx].usage++;
 
        list_for_each_entry(link, &genpd->child_links, child_node) {
                genpd_sd_counter_dec(link->parent);
@@ -3061,7 +3064,7 @@ static int idle_states_show(struct seq_file *s, void *data)
        if (ret)
                return -ERESTARTSYS;
 
-       seq_puts(s, "State          Time Spent(ms)\n");
+       seq_puts(s, "State          Time Spent(ms) Usage          Rejected\n");
 
        for (i = 0; i < genpd->state_count; i++) {
                ktime_t delta = 0;
@@ -3073,7 +3076,8 @@ static int idle_states_show(struct seq_file *s, void *data)
 
                msecs = ktime_to_ms(
                        ktime_add(genpd->states[i].idle_time, delta));
-               seq_printf(s, "S%-13i %lld\n", i, msecs);
+               seq_printf(s, "S%-13i %-14lld %-14llu %llu\n", i, msecs,
+                             genpd->states[i].usage, genpd->states[i].rejected);
        }
 
        genpd_unlock(genpd);

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index db039da..1ad0ec4 100644 (file)
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -89,6 +89,8 @@ struct genpd_power_state {
        s64 power_off_latency_ns;
        s64 power_on_latency_ns;
        s64 residency_ns;
+       u64 usage;
+       u64 rejected;
        struct fwnode_handle *fwnode;
        ktime_t idle_time;
        void *data;