[PATCH] PM / Domains: Fix compatible for domain idle state

[PATCH] PM / Domains: Fix compatible for domain idle state

[Lina Iyer]

Re-using idle state definition provided by arm,idle-state for domain
idle states creates a lot of confusion and limits further evolution of
the domain idle definition. To keep things clear and simple, define a
idle states for domain using a new compatible "domain-idle-state".

Fix existing PM domains code to look for the newly defined compatible.

Cc: <devicetree@vger.kernel.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 .../bindings/power/domain-idle-state.txt           | 33 ++++++++++++++++++++++
 .../devicetree/bindings/power/power_domain.txt     |  8 +++---
 drivers/base/power/domain.c                        |  2 +-
 3 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/domain-idle-state.txt

diff --git a/Documentation/devicetree/bindings/power/domain-idle-state.txt b/Documentation/devicetree/bindings/power/domain-idle-state.txt
new file mode 100644
index 0000000..eefc7ed
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/domain-idle-state.txt
@@ -0,0 +1,33 @@
+PM Domain Idle State Node:
+
+A domain idle state node represents the state parameters that will be used to
+select the state when there are no active components in the domain.
+
+The state node has the following parameters -
+
+- compatible:
+	Usage: Required
+	Value type: <string>
+	Definition: Must be "domain-idle-state".
+
+- entry-latency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing worst case latency in
+		    microseconds required to enter the idle state.
+		    The exit-latency-us duration may be guaranteed
+		    only after entry-latency-us has passed.
+
+- exit-latency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing worst case latency
+		    in microseconds required to exit the idle state.
+
+- min-residency-us
+	Usage: Required
+	Value type: <prop-encoded-array>
+	Definition: u32 value representing minimum residency duration
+		    in microseconds after which the idle state will yield
+		    power benefits after overcoming the overhead in entering
+i		    the idle state.
diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
index e165036..723e1ad 100644
--- a/Documentation/devicetree/bindings/power/power_domain.txt
+++ b/Documentation/devicetree/bindings/power/power_domain.txt
@@ -31,7 +31,7 @@ Optional properties:
 
 - domain-idle-states : A phandle of an idle-state that shall be soaked into a
                 generic domain power state. The idle state definitions are
-                compatible with arm,idle-state specified in [1].
+                compatible with domain-idle-state specified in [1].
   The domain-idle-state property reflects the idle state of this PM domain and
   not the idle states of the devices or sub-domains in the PM domain. Devices
   and sub-domains have their own idle-states independent of the parent
@@ -85,7 +85,7 @@ Example 3:
 	};
 
 	DOMAIN_RET: state@0 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state";
 		reg = <0x0>;
 		entry-latency-us = <1000>;
 		exit-latency-us = <2000>;
@@ -93,7 +93,7 @@ Example 3:
 	};
 
 	DOMAIN_PWR_DN: state@1 {
-		compatible = "arm,idle-state";
+		compatible = "domain-idle-state";
 		reg = <0x1>;
 		entry-latency-us = <5000>;
 		exit-latency-us = <8000>;
@@ -118,4 +118,4 @@ The node above defines a typical PM domain consumer device, which is located
 inside a PM domain with index 0 of a power controller represented by a node
 with the label "power".
 
-[1]. Documentation/devicetree/bindings/arm/idle-states.txt
+[1]. Documentation/devicetree/bindings/power/domain-idle-state.txt
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 661737c..f0bc672 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2048,7 +2048,7 @@ int genpd_dev_pm_attach(struct device *dev)
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
 static const struct of_device_id idle_state_match[] = {
-	{ .compatible = "arm,idle-state", },
+	{ .compatible = "domain-idle-state", },
 	{ }
 };
 
-- 
2.7.4

Re: [PATCH] PM / Domains: Fix compatible for domain idle state

[Lina Iyer]

On Wed, Feb 08 2017 at 09:35 -0700, Lina Iyer wrote:
>Re-using idle state definition provided by arm,idle-state for domain
>idle states creates a lot of confusion and limits further evolution of
>the domain idle definition. To keep things clear and simple, define a
>idle states for domain using a new compatible "domain-idle-state".
>
>Fix existing PM domains code to look for the newly defined compatible.
>
>Cc: <devicetree@vger.kernel.org>
>Cc: Rob Herring <robh@kernel.org>
>Signed-off-by: Lina Iyer <lina.iyer@linaro.org>

Sorry, this has already been applied. Got tagged along with the email.
Kindly ignore.

Thanks,
Lina

>---
> .../bindings/power/domain-idle-state.txt           | 33 ++++++++++++++++++++++
> .../devicetree/bindings/power/power_domain.txt     |  8 +++---
> drivers/base/power/domain.c                        |  2 +-
> 3 files changed, 38 insertions(+), 5 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/power/domain-idle-state.txt
>
>diff --git a/Documentation/devicetree/bindings/power/domain-idle-state.txt b/Documentation/devicetree/bindings/power/domain-idle-state.txt
>new file mode 100644
>index 0000000..eefc7ed
>--- /dev/null
>+++ b/Documentation/devicetree/bindings/power/domain-idle-state.txt
>@@ -0,0 +1,33 @@
>+PM Domain Idle State Node:
>+
>+A domain idle state node represents the state parameters that will be used to
>+select the state when there are no active components in the domain.
>+
>+The state node has the following parameters -
>+
>+- compatible:
>+	Usage: Required
>+	Value type: <string>
>+	Definition: Must be "domain-idle-state".
>+
>+- entry-latency-us
>+	Usage: Required
>+	Value type: <prop-encoded-array>
>+	Definition: u32 value representing worst case latency in
>+		    microseconds required to enter the idle state.
>+		    The exit-latency-us duration may be guaranteed
>+		    only after entry-latency-us has passed.
>+
>+- exit-latency-us
>+	Usage: Required
>+	Value type: <prop-encoded-array>
>+	Definition: u32 value representing worst case latency
>+		    in microseconds required to exit the idle state.
>+
>+- min-residency-us
>+	Usage: Required
>+	Value type: <prop-encoded-array>
>+	Definition: u32 value representing minimum residency duration
>+		    in microseconds after which the idle state will yield
>+		    power benefits after overcoming the overhead in entering
>+i		    the idle state.
>diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
>index e165036..723e1ad 100644
>--- a/Documentation/devicetree/bindings/power/power_domain.txt
>+++ b/Documentation/devicetree/bindings/power/power_domain.txt
>@@ -31,7 +31,7 @@ Optional properties:
>
> - domain-idle-states : A phandle of an idle-state that shall be soaked into a
>                 generic domain power state. The idle state definitions are
>-                compatible with arm,idle-state specified in [1].
>+                compatible with domain-idle-state specified in [1].
>   The domain-idle-state property reflects the idle state of this PM domain and
>   not the idle states of the devices or sub-domains in the PM domain. Devices
>   and sub-domains have their own idle-states independent of the parent
>@@ -85,7 +85,7 @@ Example 3:
> 	};
>
> 	DOMAIN_RET: state@0 {
>-		compatible = "arm,idle-state";
>+		compatible = "domain-idle-state";
> 		reg = <0x0>;
> 		entry-latency-us = <1000>;
> 		exit-latency-us = <2000>;
>@@ -93,7 +93,7 @@ Example 3:
> 	};
>
> 	DOMAIN_PWR_DN: state@1 {
>-		compatible = "arm,idle-state";
>+		compatible = "domain-idle-state";
> 		reg = <0x1>;
> 		entry-latency-us = <5000>;
> 		exit-latency-us = <8000>;
>@@ -118,4 +118,4 @@ The node above defines a typical PM domain consumer device, which is located
> inside a PM domain with index 0 of a power controller represented by a node
> with the label "power".
>
>-[1]. Documentation/devicetree/bindings/arm/idle-states.txt
>+[1]. Documentation/devicetree/bindings/power/domain-idle-state.txt
>diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>index 661737c..f0bc672 100644
>--- a/drivers/base/power/domain.c
>+++ b/drivers/base/power/domain.c
>@@ -2048,7 +2048,7 @@ int genpd_dev_pm_attach(struct device *dev)
> EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
>
> static const struct of_device_id idle_state_match[] = {
>-	{ .compatible = "arm,idle-state", },
>+	{ .compatible = "domain-idle-state", },
> 	{ }
> };
>
>-- 
>2.7.4
>

[PATCH 1/2] PM / Domains: Ignore domain-idle-states that are not compatible

[Lina Iyer]

domain-idle-states property may have phandles to idle state bindings
that may not be compatible with idle state definition defined in [1].
Such phandles would just be ignored and not throw and error when read by
the domain core.

Cc: <devicetree@vger.kernel.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 Documentation/devicetree/bindings/power/power_domain.txt |  4 +++-
 drivers/base/power/domain.c                              | 16 +++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
index 723e1ad..940707d 100644
--- a/Documentation/devicetree/bindings/power/power_domain.txt
+++ b/Documentation/devicetree/bindings/power/power_domain.txt
@@ -31,7 +31,9 @@ Optional properties:
 
 - domain-idle-states : A phandle of an idle-state that shall be soaked into a
                 generic domain power state. The idle state definitions are
-                compatible with domain-idle-state specified in [1].
+                compatible with domain-idle-state specified in [1]. phandles
+                that are not compatible with domain-idle-state will be
+                ignored.
   The domain-idle-state property reflects the idle state of this PM domain and
   not the idle states of the devices or sub-domains in the PM domain. Devices
   and sub-domains have their own idle-states independent of the parent
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 6b23d82..3825bb9 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2065,11 +2065,6 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state,
 	int err;
 	u32 residency;
 	u32 entry_latency, exit_latency;
-	const struct of_device_id *match_id;
-
-	match_id = of_match_node(idle_state_match, state_node);
-	if (!match_id)
-		return -EINVAL;
 
 	err = of_property_read_u32(state_node, "entry-latency-us",
 						&entry_latency);
@@ -2118,6 +2113,7 @@ int of_genpd_parse_idle_states(struct device_node *dn,
 	int err, ret;
 	int count;
 	struct of_phandle_iterator it;
+	const struct of_device_id *match_id;
 
 	count = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
 	if (count <= 0)
@@ -2130,6 +2126,9 @@ int of_genpd_parse_idle_states(struct device_node *dn,
 	/* Loop over the phandles until all the requested entry is found */
 	of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) {
 		np = it.node;
+		match_id = of_match_node(idle_state_match, np);
+		if (!match_id)
+			continue;
 		ret = genpd_parse_state(&st[i++], np);
 		if (ret) {
 			pr_err
@@ -2141,8 +2140,11 @@ int of_genpd_parse_idle_states(struct device_node *dn,
 		}
 	}
 
-	*n = count;
-	*states = st;
+	*n = i;
+	if (!i)
+		kfree(st);
+	else
+		*states = st;
 
 	return 0;
 }
-- 
2.7.4

Re: [PATCH 1/2] PM / Domains: Ignore domain-idle-states that are not compatible

[Ulf Hansson]

On 8 February 2017 at 17:34, Lina Iyer <lina.iyer@linaro.org> wrote:
> domain-idle-states property may have phandles to idle state bindings
> that may not be compatible with idle state definition defined in [1].

I don't find the reference to [1] in the change-log, could you please add it.

> Such phandles would just be ignored and not throw and error when read by
> the domain core.

Perhaps, you could also share a minimal snipped from a DTS as it helps
to describe why and what this change is needed.

>
> Cc: <devicetree@vger.kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  Documentation/devicetree/bindings/power/power_domain.txt |  4 +++-
>  drivers/base/power/domain.c                              | 16 +++++++++-------
>  2 files changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt
> index 723e1ad..940707d 100644
> --- a/Documentation/devicetree/bindings/power/power_domain.txt
> +++ b/Documentation/devicetree/bindings/power/power_domain.txt
> @@ -31,7 +31,9 @@ Optional properties:
>
>  - domain-idle-states : A phandle of an idle-state that shall be soaked into a
>                  generic domain power state. The idle state definitions are
> -                compatible with domain-idle-state specified in [1].
> +                compatible with domain-idle-state specified in [1]. phandles
> +                that are not compatible with domain-idle-state will be
> +                ignored.
>    The domain-idle-state property reflects the idle state of this PM domain and
>    not the idle states of the devices or sub-domains in the PM domain. Devices
>    and sub-domains have their own idle-states independent of the parent
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 6b23d82..3825bb9 100644
> --- a/drivers/base/power/domain.c

Always split DT documentation changes from the code changes and make
the DT doc changes precede the code changes in the series of patches.

> +++ b/drivers/base/power/domain.c
> @@ -2065,11 +2065,6 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state,
>         int err;
>         u32 residency;
>         u32 entry_latency, exit_latency;
> -       const struct of_device_id *match_id;
> -
> -       match_id = of_match_node(idle_state_match, state_node);
> -       if (!match_id)
> -               return -EINVAL;
>
>         err = of_property_read_u32(state_node, "entry-latency-us",
>                                                 &entry_latency);
> @@ -2118,6 +2113,7 @@ int of_genpd_parse_idle_states(struct device_node *dn,
>         int err, ret;
>         int count;
>         struct of_phandle_iterator it;
> +       const struct of_device_id *match_id;
>
>         count = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
>         if (count <= 0)
> @@ -2130,6 +2126,9 @@ int of_genpd_parse_idle_states(struct device_node *dn,
>         /* Loop over the phandles until all the requested entry is found */
>         of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) {
>                 np = it.node;
> +               match_id = of_match_node(idle_state_match, np);
> +               if (!match_id)
> +                       continue;

Earlier we have allocated "count" numbers of struct genpd_power_state,
by using a kcalloc().

This change may lead to that we could have allocated more memory than
actually needed - because there may be some nodes that doesn't match.

Perhaps it's better to do a pre-iteration to find the real numbers of
how many struct genpd_power_state we actually need to allocate!?

>                 ret = genpd_parse_state(&st[i++], np);
>                 if (ret) {
>                         pr_err
> @@ -2141,8 +2140,11 @@ int of_genpd_parse_idle_states(struct device_node *dn,
>                 }
>         }
>
> -       *n = count;
> -       *states = st;
> +       *n = i;
> +       if (!i)
> +               kfree(st);
> +       else
> +               *states = st;
>
>         return 0;
>  }
> --
> 2.7.4
>

Kind regards
Uffe