[PATCH 0/3] pmdomain: core: Extend domain idle states debugfs support

[PATCH 0/3] pmdomain: core: Extend domain idle states debugfs support

[Ulf Hansson]

This small series moves around and extends the information that genpd shows for
the domain idle states in debugs.

Please help review and test!

Kind regards
Ulf Hansson

Ulf Hansson (3):
  pmdomain: core: Restructure domain idle states data for genpd in
    debugfs
  pmdomain: core: Show latency/residency for domain idle states in
    debugfs
  pmdomain: core: Extend statistics for domain idle states with s2idle
    data

 drivers/pmdomain/core.c   | 59 +++++++++++++++++++++++++++++++++------
 include/linux/pm_domain.h |  1 +
 2 files changed, 51 insertions(+), 9 deletions(-)

-- 
2.43.0

[PATCH 1/3] pmdomain: core: Restructure domain idle states data for genpd in debugfs

[Ulf Hansson]

To prepare for additional information to be added for the domain idle
states in genpd's debugfs, let's make the existing information denser. To
allow that, let's move the static information of the domain idle states
into a separate debugfs file.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/pmdomain/core.c | 43 ++++++++++++++++++++++++++++++++---------
 1 file changed, 34 insertions(+), 9 deletions(-)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index bf82775f6a67..919dff2081d6 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -3772,11 +3772,11 @@ static int idle_states_show(struct seq_file *s, void *data)
 	if (ret)
 		return -ERESTARTSYS;
 
-	seq_puts(s, "State          Time Spent(ms) Usage      Rejected   Above      Below\n");
+	seq_puts(s, "State  Time(ms)       Usage      Rejected   Above      Below\n");
 
 	for (i = 0; i < genpd->state_count; i++) {
 		struct genpd_power_state *state = &genpd->states[i];
-		char state_name[15];
+		char state_name[7];
 
 		idle_time += state->idle_time;
 
@@ -3788,14 +3788,36 @@ static int idle_states_show(struct seq_file *s, void *data)
 			}
 		}
 
-		if (!state->name)
-			snprintf(state_name, ARRAY_SIZE(state_name), "S%-13d", i);
-
+		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
 		do_div(idle_time, NSEC_PER_MSEC);
-		seq_printf(s, "%-14s %-14llu %-10llu %-10llu %-10llu %llu\n",
-			   state->name ?: state_name, idle_time,
-			   state->usage, state->rejected, state->above,
-			   state->below);
+		seq_printf(s, "%-6s %-14llu %-10llu %-10llu %-10llu %llu\n",
+			   state_name, idle_time, state->usage, state->rejected,
+			   state->above, state->below);
+	}
+
+	genpd_unlock(genpd);
+	return ret;
+}
+
+static int idle_states_desc_show(struct seq_file *s, void *data)
+{
+	struct generic_pm_domain *genpd = s->private;
+	unsigned int i;
+	int ret = 0;
+
+	ret = genpd_lock_interruptible(genpd);
+	if (ret)
+		return -ERESTARTSYS;
+
+	seq_puts(s, "State  Name\n");
+
+	for (i = 0; i < genpd->state_count; i++) {
+		struct genpd_power_state *state = &genpd->states[i];
+		char state_name[7];
+
+		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
+		seq_printf(s, "%-6s %s\n",
+			   state_name, state->name ?: "N/A");
 	}
 
 	genpd_unlock(genpd);
@@ -3891,6 +3913,7 @@ DEFINE_SHOW_ATTRIBUTE(summary);
 DEFINE_SHOW_ATTRIBUTE(status);
 DEFINE_SHOW_ATTRIBUTE(sub_domains);
 DEFINE_SHOW_ATTRIBUTE(idle_states);
+DEFINE_SHOW_ATTRIBUTE(idle_states_desc);
 DEFINE_SHOW_ATTRIBUTE(active_time);
 DEFINE_SHOW_ATTRIBUTE(total_idle_time);
 DEFINE_SHOW_ATTRIBUTE(devices);
@@ -3911,6 +3934,8 @@ static void genpd_debug_add(struct generic_pm_domain *genpd)
 			    d, genpd, &sub_domains_fops);
 	debugfs_create_file("idle_states", 0444,
 			    d, genpd, &idle_states_fops);
+	debugfs_create_file("idle_states_desc", 0444,
+			    d, genpd, &idle_states_desc_fops);
 	debugfs_create_file("active_time", 0444,
 			    d, genpd, &active_time_fops);
 	debugfs_create_file("total_idle_time", 0444,
-- 
2.43.0

[PATCH 2/3] pmdomain: core: Show latency/residency for domain idle states in debugfs

[Ulf Hansson]

Similar to how cpuidle provides the values for latency and residency for
CPU's idle states through sysfs, let's make the corresponding data for PM
domain's idle states available for user space, via genpd's debugfs support.

Suggested-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/pmdomain/core.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 919dff2081d6..bf512ff0857d 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -3809,15 +3809,24 @@ static int idle_states_desc_show(struct seq_file *s, void *data)
 	if (ret)
 		return -ERESTARTSYS;
 
-	seq_puts(s, "State  Name\n");
+	seq_puts(s, "State  Latency(us)  Residency(us)  Name\n");
 
 	for (i = 0; i < genpd->state_count; i++) {
 		struct genpd_power_state *state = &genpd->states[i];
+		u64 latency, residency;
 		char state_name[7];
 
+		latency = state->power_off_latency_ns +
+			state->power_on_latency_ns;
+		do_div(latency, NSEC_PER_USEC);
+
+		residency = state->residency_ns;
+		do_div(residency, NSEC_PER_USEC);
+
 		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
-		seq_printf(s, "%-6s %s\n",
-			   state_name, state->name ?: "N/A");
+		seq_printf(s, "%-6s %-12llu %-14llu %s\n",
+			   state_name, latency, residency,
+			   state->name ?: "N/A");
 	}
 
 	genpd_unlock(genpd);
-- 
2.43.0

[PATCH 3/3] pmdomain: core: Extend statistics for domain idle states with s2idle data

[Ulf Hansson]

To allow user space to monitor the selection of the domain idle state
during s2idle for a CPU PM domain, let's extend the debugfs support in
genpd with this information.

Suggested-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/pmdomain/core.c   | 13 ++++++++++---
 include/linux/pm_domain.h |  1 +
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index bf512ff0857d..bb04cb7ccdcd 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -1438,6 +1438,13 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
 		return;
 	} else {
 		genpd->states[genpd->state_idx].usage++;
+
+		/*
+		 * The ->system_power_down_ok() callback is currently used only
+		 * for s2idle. Use it to know when to update the usage counter.
+		 */
+		if (genpd->gov && genpd->gov->system_power_down_ok)
+			genpd->states[genpd->state_idx].usage_s2idle++;
 	}
 
 	genpd->status = GENPD_STATE_OFF;
@@ -3772,7 +3779,7 @@ static int idle_states_show(struct seq_file *s, void *data)
 	if (ret)
 		return -ERESTARTSYS;
 
-	seq_puts(s, "State  Time(ms)       Usage      Rejected   Above      Below\n");
+	seq_puts(s, "State  Time(ms)       Usage      Rejected   Above      Below      S2idle\n");
 
 	for (i = 0; i < genpd->state_count; i++) {
 		struct genpd_power_state *state = &genpd->states[i];
@@ -3790,9 +3797,9 @@ static int idle_states_show(struct seq_file *s, void *data)
 
 		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
 		do_div(idle_time, NSEC_PER_MSEC);
-		seq_printf(s, "%-6s %-14llu %-10llu %-10llu %-10llu %llu\n",
+		seq_printf(s, "%-6s %-14llu %-10llu %-10llu %-10llu %-10llu %llu\n",
 			   state_name, idle_time, state->usage, state->rejected,
-			   state->above, state->below);
+			   state->above, state->below, state->usage_s2idle);
 	}
 
 	genpd_unlock(genpd);
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 93ba0143ca47..f6f6d494f728 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -183,6 +183,7 @@ struct genpd_power_state {
 	u64 rejected;
 	u64 above;
 	u64 below;
+	u64 usage_s2idle;
 	struct fwnode_handle *fwnode;
 	u64 idle_time;
 	void *data;
-- 
2.43.0

Re: [PATCH 3/3] pmdomain: core: Extend statistics for domain idle states with s2idle data

[Dhruva Gole]

On Jan 19, 2026 at 15:31:15 +0100, Ulf Hansson wrote:
> To allow user space to monitor the selection of the domain idle state
> during s2idle for a CPU PM domain, let's extend the debugfs support in
> genpd with this information.
> 
> Suggested-by: Dhruva Gole <d-gole@ti.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/pmdomain/core.c   | 13 ++++++++++---
>  include/linux/pm_domain.h |  1 +
>  2 files changed, 11 insertions(+), 3 deletions(-)

This will be quite helpful, thanks alot Ulf!
Reviewed-by: Dhruva Gole <d-gole@ti.com>

> 
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index bf512ff0857d..bb04cb7ccdcd 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -1438,6 +1438,13 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
>  		return;
>  	} else {
>  		genpd->states[genpd->state_idx].usage++;
> +
> +		/*
> +		 * The ->system_power_down_ok() callback is currently used only
> +		 * for s2idle. Use it to know when to update the usage counter.
> +		 */
> +		if (genpd->gov && genpd->gov->system_power_down_ok)
> +			genpd->states[genpd->state_idx].usage_s2idle++;
>  	}
>  
>  	genpd->status = GENPD_STATE_OFF;
> @@ -3772,7 +3779,7 @@ static int idle_states_show(struct seq_file *s, void *data)
>  	if (ret)
>  		return -ERESTARTSYS;
>  
> -	seq_puts(s, "State  Time(ms)       Usage      Rejected   Above      Below\n");
> +	seq_puts(s, "State  Time(ms)       Usage      Rejected   Above      Below      S2idle\n");
>  
>  	for (i = 0; i < genpd->state_count; i++) {
>  		struct genpd_power_state *state = &genpd->states[i];
> @@ -3790,9 +3797,9 @@ static int idle_states_show(struct seq_file *s, void *data)
>  
>  		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
>  		do_div(idle_time, NSEC_PER_MSEC);
> -		seq_printf(s, "%-6s %-14llu %-10llu %-10llu %-10llu %llu\n",
> +		seq_printf(s, "%-6s %-14llu %-10llu %-10llu %-10llu %-10llu %llu\n",
>  			   state_name, idle_time, state->usage, state->rejected,
> -			   state->above, state->below);
> +			   state->above, state->below, state->usage_s2idle);
>  	}
>  
>  	genpd_unlock(genpd);
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 93ba0143ca47..f6f6d494f728 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -183,6 +183,7 @@ struct genpd_power_state {
>  	u64 rejected;
>  	u64 above;
>  	u64 below;
> +	u64 usage_s2idle;
>  	struct fwnode_handle *fwnode;
>  	u64 idle_time;
>  	void *data;
> -- 
> 2.43.0
> 

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH 2/3] pmdomain: core: Show latency/residency for domain idle states in debugfs

[Dhruva Gole]

On Jan 19, 2026 at 15:31:14 +0100, Ulf Hansson wrote:
> Similar to how cpuidle provides the values for latency and residency for
> CPU's idle states through sysfs, let's make the corresponding data for PM
> domain's idle states available for user space, via genpd's debugfs support.
> 
> Suggested-by: Dhruva Gole <d-gole@ti.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/pmdomain/core.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index 919dff2081d6..bf512ff0857d 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -3809,15 +3809,24 @@ static int idle_states_desc_show(struct seq_file *s, void *data)
>  	if (ret)
>  		return -ERESTARTSYS;
>  
> -	seq_puts(s, "State  Name\n");
> +	seq_puts(s, "State  Latency(us)  Residency(us)  Name\n");
>  
>  	for (i = 0; i < genpd->state_count; i++) {
>  		struct genpd_power_state *state = &genpd->states[i];
> +		u64 latency, residency;
>  		char state_name[7];
>  
> +		latency = state->power_off_latency_ns +
> +			state->power_on_latency_ns;
> +		do_div(latency, NSEC_PER_USEC);
> +
> +		residency = state->residency_ns;
> +		do_div(residency, NSEC_PER_USEC);
> +
>  		snprintf(state_name, ARRAY_SIZE(state_name), "S%-5d", i);
> -		seq_printf(s, "%-6s %s\n",
> -			   state_name, state->name ?: "N/A");
> +		seq_printf(s, "%-6s %-12llu %-14llu %s\n",
> +			   state_name, latency, residency,
> +			   state->name ?: "N/A");

Much needed indeed, thanks!!

Reviewed-by: Dhruva Gole <d-gole@ti.com>

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated

Re: [PATCH 0/3] pmdomain: core: Extend domain idle states debugfs support

[Ulf Hansson]

On Mon, 19 Jan 2026 at 15:31, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> This small series moves around and extends the information that genpd shows for
> the domain idle states in debugs.
>
> Please help review and test!
>
> Kind regards
> Ulf Hansson
>
> Ulf Hansson (3):
>   pmdomain: core: Restructure domain idle states data for genpd in
>     debugfs
>   pmdomain: core: Show latency/residency for domain idle states in
>     debugfs
>   pmdomain: core: Extend statistics for domain idle states with s2idle
>     data
>
>  drivers/pmdomain/core.c   | 59 +++++++++++++++++++++++++++++++++------
>  include/linux/pm_domain.h |  1 +
>  2 files changed, 51 insertions(+), 9 deletions(-)
>
> --
> 2.43.0
>

FYI, the series has been applied for next!

Kind regards
Uffe

Re: [PATCH 0/3] pmdomain: core: Extend domain idle states debugfs support

[Kevin Hilman]

Ulf Hansson <ulf.hansson@linaro.org> writes:

> This small series moves around and extends the information that genpd shows for
> the domain idle states in debugs.
>
> Please help review and test!

Reviewed-by: Kevin Hilman <khilman@baylibre.com>