[RFC 7/7] PM / Domains: add debugfs 'states' and 'timings' seq files

From: Marc Titinger
Date: Fri Sep 25 2015 - 09:06:23 EST


From: Marc Titinger <mtitinger@xxxxxxxxxxxx>

This purpose of these debug seq-files is to help investigate
generic power domain state transitions, based on device constraints.
requires the "multiple states" patches from Axel Haslam.

also rename 'summary' from 'pm_genpd_summary'

sample output for 'states'
==========================

Domain State name Eval = 2200nter + Exit = Min_off_on (ns)
-----------------------------------------------------------------------
a53_pd cluster-sleep-0 1500000+800000=2300000
a57_pd d1-retention 1000000+800000=1800000
a57_pd cluster-sleep-0 1500000+800000=2300000

sample output for 'timings'
===========================

Domain Devices, Timings in ns
Stop/Start Save/Restore, Effective
---------------------------------------------------- ---
a53_pd
/cpus/cpu@100 1060 /660 1580 /1940 ,0 (cached stop)
/cpus/cpu@101 1060 /740 1520 /1600 ,0 (cached stop)
/cpus/cpu@102 880 /620 1380 /1780 ,0 (cached stop)
/cpus/cpu@103 1080 /640 1340 /1600 ,0 (cached stop)
a57_pd
/cpus/cpu@0 1160 /740 3280 /1800 ,0 (cached stop)
/cpus/cpu@1 780 /1400 1440 /2080 ,0 (cached stop)
/D1 600 /540 7140 /6420 ,2199460 (cached stop)

Signed-off-by: Marc Titinger <mtitinger@xxxxxxxxxxxx>
---
drivers/base/power/domain.c | 107 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 105 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index b747e9e..59ccd92 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2606,6 +2606,96 @@ static const struct file_operations pm_genpd_summary_fops = {
.release = single_release,
};

+static int pm_genpd_states_show(struct seq_file *s, void *data)
+{
+ struct generic_pm_domain *genpd;
+
+ seq_puts(s,
+ "\n Domain State name Enter + Exit = Min_off_on (ns)\n");
+ seq_puts(s,
+ "-----------------------------------------------------------------------\n");
+
+ list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
+
+ int i;
+
+ for (i = 0; i < genpd->state_count; i++) {
+ seq_printf(s, "%-20s %-20s %lld+%lld=%lld\n",
+ genpd->name,
+ genpd->states[i].name,
+ genpd->states[i].power_on_latency_ns,
+ genpd->states[i].power_off_latency_ns,
+ genpd->states[i].power_off_latency_ns
+ + genpd->states[i].power_on_latency_ns);
+ }
+
+ }
+
+ seq_puts(s, "\n");
+
+ return 0;
+}
+
+static int pm_genpd_states_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pm_genpd_states_show, NULL);
+}
+
+static const struct file_operations pm_genpd_states_fops = {
+ .open = pm_genpd_states_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int pm_genpd_timing_show(struct seq_file *s, void *data)
+{
+ struct generic_pm_domain *genpd;
+
+ seq_puts(s, "\n Domain Devices, Timings in ns\n");
+ seq_puts(s,
+ " Stop/Start Save/Restore, Effective\n");
+ seq_puts(s,
+ "---------------------------------------------------- ---\n");
+
+ list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
+ struct pm_domain_data *pm_data;
+
+ seq_printf(s, "%-30s", genpd->name);
+
+ list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
+ struct gpd_timing_data *td = &to_gpd_data(pm_data)->td;
+
+ if (!pm_data->dev->of_node)
+ continue;
+
+ seq_printf(s,
+ "\n %-20s %-6lld/%-6lld %-6lld/%-6lld,%lld %s%s",
+ pm_data->dev->of_node->full_name,
+ td->stop_latency_ns, td->start_latency_ns,
+ td->save_state_latency_ns,
+ td->restore_state_latency_ns,
+ td->effective_constraint_ns,
+ td->cached_stop_ok ? "(cached stop) " : "",
+ td->constraint_changed ? "(changed)" : "");
+ }
+ seq_puts(s, "\n");
+ }
+ return 0;
+}
+
+static int pm_genpd_timing_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pm_genpd_timing_show, NULL);
+}
+
+static const struct file_operations pm_genpd_timing_fops = {
+ .open = pm_genpd_timing_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static int __init pm_genpd_debug_init(void)
{
struct dentry *d;
@@ -2615,8 +2705,21 @@ static int __init pm_genpd_debug_init(void)
if (!pm_genpd_debugfs_dir)
return -ENOMEM;

- d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
- pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops);
+ d = debugfs_create_file("summary", S_IRUGO,
+ pm_genpd_debugfs_dir, NULL,
+ &pm_genpd_summary_fops);
+ if (!d)
+ return -ENOMEM;
+
+ d = debugfs_create_file("states", S_IRUGO,
+ pm_genpd_debugfs_dir, NULL,
+ &pm_genpd_states_fops);
+ if (!d)
+ return -ENOMEM;
+
+ d = debugfs_create_file("timings", S_IRUGO,
+ pm_genpd_debugfs_dir, NULL,
+ &pm_genpd_timing_fops);
if (!d)
return -ENOMEM;

--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/