diff mbox series

[v5,1/2] PM / Domains: Add support for 'required-opps' to set default perf state

Message ID 1626764876-10229-2-git-send-email-rnayak@codeaurora.org
State New
Headers show
Series [v5,1/2] PM / Domains: Add support for 'required-opps' to set default perf state | expand

Commit Message

Rajendra Nayak July 20, 2021, 7:07 a.m. UTC
Some devices within power domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. They can express this using the 'required-opps'
property in device tree, which points to the phandle of the OPP
supported by the corresponding power-domains.

Add support to parse this information from DT and then set the
specified performance state during attach and drop it on detach.
runtime suspend/resume callbacks already have logic to drop/set
the vote as needed and should take care of dropping the default
perf state vote on runtime suspend and restore it back on runtime
resume.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 drivers/base/power/domain.c | 28 +++++++++++++++++++++++++---
 include/linux/pm_domain.h   |  1 +
 2 files changed, 26 insertions(+), 3 deletions(-)

Comments

Ulf Hansson Aug. 2, 2021, 12:59 p.m. UTC | #1
On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <rnayak@codeaurora.org> wrote:
>

> Some devices within power domains with performance states do not

> support DVFS, but still need to vote on a default/static state

> while they are active. They can express this using the 'required-opps'

> property in device tree, which points to the phandle of the OPP

> supported by the corresponding power-domains.

>

> Add support to parse this information from DT and then set the

> specified performance state during attach and drop it on detach.

> runtime suspend/resume callbacks already have logic to drop/set

> the vote as needed and should take care of dropping the default

> perf state vote on runtime suspend and restore it back on runtime

> resume.

>

> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>

> ---

>  drivers/base/power/domain.c | 28 +++++++++++++++++++++++++---

>  include/linux/pm_domain.h   |  1 +

>  2 files changed, 26 insertions(+), 3 deletions(-)

>

> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c

> index a934c67..f454031 100644

> --- a/drivers/base/power/domain.c

> +++ b/drivers/base/power/domain.c

> @@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)

>

>         dev_dbg(dev, "removing from PM domain %s\n", pd->name);

>

> +       /* Drop the default performance state */

> +       if (dev_gpd_data(dev)->default_pstate) {

> +               dev_pm_genpd_set_performance_state(dev, 0);

> +               dev_gpd_data(dev)->default_pstate = 0;

> +       }

> +

>         for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {

>                 ret = genpd_remove_device(pd, dev);

>                 if (ret != -EAGAIN)

> @@ -2635,9 +2641,10 @@ static void genpd_dev_pm_sync(struct device *dev)

>  static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

>                                  unsigned int index, bool power_on)

>  {

> +       struct device_node *np;

>         struct of_phandle_args pd_args;

>         struct generic_pm_domain *pd;

> -       int ret;

> +       int ret, pstate;

>

>         ret = of_parse_phandle_with_args(dev->of_node, "power-domains",

>                                 "#power-domain-cells", index, &pd_args);

> @@ -2675,10 +2682,25 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

>                 genpd_unlock(pd);

>         }

>

> -       if (ret)

> +       if (ret) {

>                 genpd_remove_device(pd, dev);

> +               return -EPROBE_DEFER;

> +       }

> +

> +       /* Set the default performance state */

> +       np = base_dev->of_node;


Please use dev->of_node instead (it is set to the same of_node as
base_dev by the callers of __genpd_dev_pm_attach) as it's more
consistent with existing code.

> +       if (of_parse_phandle(np, "required-opps", index)) {

> +               pstate = of_get_required_opp_performance_state(np, index);

> +               if (pstate < 0) {

> +                       ret = pstate;

> +                       dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",

> +                               pd->name, ret);

> +               }

> +               dev_pm_genpd_set_performance_state(dev, pstate);

> +               dev_gpd_data(dev)->default_pstate = pstate;


This doesn't look entirely correct to me. If we fail to translate a
required opp to a performance state, we shouldn't try to set it.

Perhaps it's also easier to call
of_get_required_opp_performance_state() unconditionally of whether a
"required-opps" specifier exists. If it fails with the translation,
then we just skip setting a default state and continue with returning
1.

Would that work?

> +       }

>

> -       return ret ? -EPROBE_DEFER : 1;

> +       return ret ? ret : 1;

>  }

>

>  /**

> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h

> index 21a0577..67017c9 100644

> --- a/include/linux/pm_domain.h

> +++ b/include/linux/pm_domain.h

> @@ -198,6 +198,7 @@ struct generic_pm_domain_data {

>         struct notifier_block *power_nb;

>         int cpu;

>         unsigned int performance_state;

> +       unsigned int default_pstate;

>         unsigned int rpm_pstate;

>         ktime_t next_wakeup;

>         void *data;

> --

> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member

> of Code Aurora Forum, hosted by The Linux Foundation

>


Kind regards
Uffe
Rajendra Nayak Aug. 3, 2021, 4:38 a.m. UTC | #2
On 8/2/2021 6:29 PM, Ulf Hansson wrote:
> On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <rnayak@codeaurora.org> wrote:

>>

>> Some devices within power domains with performance states do not

>> support DVFS, but still need to vote on a default/static state

>> while they are active. They can express this using the 'required-opps'

>> property in device tree, which points to the phandle of the OPP

>> supported by the corresponding power-domains.

>>

>> Add support to parse this information from DT and then set the

>> specified performance state during attach and drop it on detach.

>> runtime suspend/resume callbacks already have logic to drop/set

>> the vote as needed and should take care of dropping the default

>> perf state vote on runtime suspend and restore it back on runtime

>> resume.

>>

>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>

>> ---

>>   drivers/base/power/domain.c | 28 +++++++++++++++++++++++++---

>>   include/linux/pm_domain.h   |  1 +

>>   2 files changed, 26 insertions(+), 3 deletions(-)

>>

>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c

>> index a934c67..f454031 100644

>> --- a/drivers/base/power/domain.c

>> +++ b/drivers/base/power/domain.c

>> @@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)

>>

>>          dev_dbg(dev, "removing from PM domain %s\n", pd->name);

>>

>> +       /* Drop the default performance state */

>> +       if (dev_gpd_data(dev)->default_pstate) {

>> +               dev_pm_genpd_set_performance_state(dev, 0);

>> +               dev_gpd_data(dev)->default_pstate = 0;

>> +       }

>> +

>>          for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {

>>                  ret = genpd_remove_device(pd, dev);

>>                  if (ret != -EAGAIN)

>> @@ -2635,9 +2641,10 @@ static void genpd_dev_pm_sync(struct device *dev)

>>   static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

>>                                   unsigned int index, bool power_on)

>>   {

>> +       struct device_node *np;

>>          struct of_phandle_args pd_args;

>>          struct generic_pm_domain *pd;

>> -       int ret;

>> +       int ret, pstate;

>>

>>          ret = of_parse_phandle_with_args(dev->of_node, "power-domains",

>>                                  "#power-domain-cells", index, &pd_args);

>> @@ -2675,10 +2682,25 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

>>                  genpd_unlock(pd);

>>          }

>>

>> -       if (ret)

>> +       if (ret) {

>>                  genpd_remove_device(pd, dev);

>> +               return -EPROBE_DEFER;

>> +       }

>> +

>> +       /* Set the default performance state */

>> +       np = base_dev->of_node;

> 

> Please use dev->of_node instead (it is set to the same of_node as

> base_dev by the callers of __genpd_dev_pm_attach) as it's more

> consistent with existing code.

> 

>> +       if (of_parse_phandle(np, "required-opps", index)) {

>> +               pstate = of_get_required_opp_performance_state(np, index);

>> +               if (pstate < 0) {

>> +                       ret = pstate;

>> +                       dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",

>> +                               pd->name, ret);

>> +               }

>> +               dev_pm_genpd_set_performance_state(dev, pstate);

>> +               dev_gpd_data(dev)->default_pstate = pstate;

> 

> This doesn't look entirely correct to me. If we fail to translate a

> required opp to a performance state, we shouldn't try to set it.


yeah, that does not seem right at all :(

> Perhaps it's also easier to call

> of_get_required_opp_performance_state() unconditionally of whether a

> "required-opps" specifier exists. If it fails with the translation,

> then we just skip setting a default state and continue with returning

> 1.

> 

> Would that work?


I think it should, I'll redo the error handling, hopefully right this time,
and re-post. Thanks for the review.

> 

>> +       }

>>

>> -       return ret ? -EPROBE_DEFER : 1;

>> +       return ret ? ret : 1;

>>   }

>>

>>   /**

>> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h

>> index 21a0577..67017c9 100644

>> --- a/include/linux/pm_domain.h

>> +++ b/include/linux/pm_domain.h

>> @@ -198,6 +198,7 @@ struct generic_pm_domain_data {

>>          struct notifier_block *power_nb;

>>          int cpu;

>>          unsigned int performance_state;

>> +       unsigned int default_pstate;

>>          unsigned int rpm_pstate;

>>          ktime_t next_wakeup;

>>          void *data;

>> --

>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member

>> of Code Aurora Forum, hosted by The Linux Foundation

>>

> 

> Kind regards

> Uffe

> 


-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
Rajendra Nayak Aug. 4, 2021, 11:08 a.m. UTC | #3
On 8/3/2021 10:08 AM, Rajendra Nayak wrote:
> 
> On 8/2/2021 6:29 PM, Ulf Hansson wrote:
>> On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <rnayak@codeaurora.org> wrote:
>>>
>>> Some devices within power domains with performance states do not
>>> support DVFS, but still need to vote on a default/static state
>>> while they are active. They can express this using the 'required-opps'
>>> property in device tree, which points to the phandle of the OPP
>>> supported by the corresponding power-domains.
>>>
>>> Add support to parse this information from DT and then set the
>>> specified performance state during attach and drop it on detach.
>>> runtime suspend/resume callbacks already have logic to drop/set
>>> the vote as needed and should take care of dropping the default
>>> perf state vote on runtime suspend and restore it back on runtime
>>> resume.
>>>
>>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>>> ---
>>>   drivers/base/power/domain.c | 28 +++++++++++++++++++++++++---
>>>   include/linux/pm_domain.h   |  1 +
>>>   2 files changed, 26 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>>> index a934c67..f454031 100644
>>> --- a/drivers/base/power/domain.c
>>> +++ b/drivers/base/power/domain.c
>>> @@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
>>>
>>>          dev_dbg(dev, "removing from PM domain %s\n", pd->name);
>>>
>>> +       /* Drop the default performance state */
>>> +       if (dev_gpd_data(dev)->default_pstate) {
>>> +               dev_pm_genpd_set_performance_state(dev, 0);
>>> +               dev_gpd_data(dev)->default_pstate = 0;
>>> +       }
>>> +
>>>          for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
>>>                  ret = genpd_remove_device(pd, dev);
>>>                  if (ret != -EAGAIN)
>>> @@ -2635,9 +2641,10 @@ static void genpd_dev_pm_sync(struct device *dev)
>>>   static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>>>                                   unsigned int index, bool power_on)
>>>   {
>>> +       struct device_node *np;
>>>          struct of_phandle_args pd_args;
>>>          struct generic_pm_domain *pd;
>>> -       int ret;
>>> +       int ret, pstate;
>>>
>>>          ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
>>>                                  "#power-domain-cells", index, &pd_args);
>>> @@ -2675,10 +2682,25 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>>>                  genpd_unlock(pd);
>>>          }
>>>
>>> -       if (ret)
>>> +       if (ret) {
>>>                  genpd_remove_device(pd, dev);
>>> +               return -EPROBE_DEFER;
>>> +       }
>>> +
>>> +       /* Set the default performance state */
>>> +       np = base_dev->of_node;
>>
>> Please use dev->of_node instead (it is set to the same of_node as
>> base_dev by the callers of __genpd_dev_pm_attach) as it's more
>> consistent with existing code.
>>
>>> +       if (of_parse_phandle(np, "required-opps", index)) {
>>> +               pstate = of_get_required_opp_performance_state(np, index);
>>> +               if (pstate < 0) {
>>> +                       ret = pstate;
>>> +                       dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
>>> +                               pd->name, ret);
>>> +               }
>>> +               dev_pm_genpd_set_performance_state(dev, pstate);
>>> +               dev_gpd_data(dev)->default_pstate = pstate;
>>
>> This doesn't look entirely correct to me. If we fail to translate a
>> required opp to a performance state, we shouldn't try to set it.
> 
> yeah, that does not seem right at all :(
> 
>> Perhaps it's also easier to call
>> of_get_required_opp_performance_state() unconditionally of whether a
>> "required-opps" specifier exists. If it fails with the translation,
>> then we just skip setting a default state and continue with returning
>> 1.
>>
>> Would that work?

Looks like calling of_get_required_opp_performance_state() unconditionally
makes it spit out a pr_err() in case the node is missing "required-opps" property,
so I posted a v6 [1] with the check in place and adding the missing else
condition.

[1] https://lore.kernel.org/patchwork/project/lkml/list/?series=510727
Ulf Hansson Aug. 4, 2021, 11:39 a.m. UTC | #4
On Wed, 4 Aug 2021 at 13:08, Rajendra Nayak <rnayak@codeaurora.org> wrote:
>

>

> On 8/3/2021 10:08 AM, Rajendra Nayak wrote:

> >

> > On 8/2/2021 6:29 PM, Ulf Hansson wrote:

> >> On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <rnayak@codeaurora.org> wrote:

> >>>

> >>> Some devices within power domains with performance states do not

> >>> support DVFS, but still need to vote on a default/static state

> >>> while they are active. They can express this using the 'required-opps'

> >>> property in device tree, which points to the phandle of the OPP

> >>> supported by the corresponding power-domains.

> >>>

> >>> Add support to parse this information from DT and then set the

> >>> specified performance state during attach and drop it on detach.

> >>> runtime suspend/resume callbacks already have logic to drop/set

> >>> the vote as needed and should take care of dropping the default

> >>> perf state vote on runtime suspend and restore it back on runtime

> >>> resume.

> >>>

> >>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>

> >>> ---

> >>>   drivers/base/power/domain.c | 28 +++++++++++++++++++++++++---

> >>>   include/linux/pm_domain.h   |  1 +

> >>>   2 files changed, 26 insertions(+), 3 deletions(-)

> >>>

> >>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c

> >>> index a934c67..f454031 100644

> >>> --- a/drivers/base/power/domain.c

> >>> +++ b/drivers/base/power/domain.c

> >>> @@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)

> >>>

> >>>          dev_dbg(dev, "removing from PM domain %s\n", pd->name);

> >>>

> >>> +       /* Drop the default performance state */

> >>> +       if (dev_gpd_data(dev)->default_pstate) {

> >>> +               dev_pm_genpd_set_performance_state(dev, 0);

> >>> +               dev_gpd_data(dev)->default_pstate = 0;

> >>> +       }

> >>> +

> >>>          for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {

> >>>                  ret = genpd_remove_device(pd, dev);

> >>>                  if (ret != -EAGAIN)

> >>> @@ -2635,9 +2641,10 @@ static void genpd_dev_pm_sync(struct device *dev)

> >>>   static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

> >>>                                   unsigned int index, bool power_on)

> >>>   {

> >>> +       struct device_node *np;

> >>>          struct of_phandle_args pd_args;

> >>>          struct generic_pm_domain *pd;

> >>> -       int ret;

> >>> +       int ret, pstate;

> >>>

> >>>          ret = of_parse_phandle_with_args(dev->of_node, "power-domains",

> >>>                                  "#power-domain-cells", index, &pd_args);

> >>> @@ -2675,10 +2682,25 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,

> >>>                  genpd_unlock(pd);

> >>>          }

> >>>

> >>> -       if (ret)

> >>> +       if (ret) {

> >>>                  genpd_remove_device(pd, dev);

> >>> +               return -EPROBE_DEFER;

> >>> +       }

> >>> +

> >>> +       /* Set the default performance state */

> >>> +       np = base_dev->of_node;

> >>

> >> Please use dev->of_node instead (it is set to the same of_node as

> >> base_dev by the callers of __genpd_dev_pm_attach) as it's more

> >> consistent with existing code.

> >>

> >>> +       if (of_parse_phandle(np, "required-opps", index)) {

> >>> +               pstate = of_get_required_opp_performance_state(np, index);

> >>> +               if (pstate < 0) {

> >>> +                       ret = pstate;

> >>> +                       dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",

> >>> +                               pd->name, ret);

> >>> +               }

> >>> +               dev_pm_genpd_set_performance_state(dev, pstate);

> >>> +               dev_gpd_data(dev)->default_pstate = pstate;

> >>

> >> This doesn't look entirely correct to me. If we fail to translate a

> >> required opp to a performance state, we shouldn't try to set it.

> >

> > yeah, that does not seem right at all :(

> >

> >> Perhaps it's also easier to call

> >> of_get_required_opp_performance_state() unconditionally of whether a

> >> "required-opps" specifier exists. If it fails with the translation,

> >> then we just skip setting a default state and continue with returning

> >> 1.

> >>

> >> Would that work?

>

> Looks like calling of_get_required_opp_performance_state() unconditionally

> makes it spit out a pr_err() in case the node is missing "required-opps" property,

> so I posted a v6 [1] with the check in place and adding the missing else

> condition.


I see.

Viresh, would it make sense to remove that print? I mean, the
required-opps property could be considered as optional and it seems a
bit silly that a pre-parsing of the property is needed to figure that
out.

>

> [1] https://lore.kernel.org/patchwork/project/lkml/list/?series=510727


Kind regards
Uffe
diff mbox series

Patch

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a934c67..f454031 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2598,6 +2598,12 @@  static void genpd_dev_pm_detach(struct device *dev, bool power_off)
 
 	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
 
+	/* Drop the default performance state */
+	if (dev_gpd_data(dev)->default_pstate) {
+		dev_pm_genpd_set_performance_state(dev, 0);
+		dev_gpd_data(dev)->default_pstate = 0;
+	}
+
 	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
 		ret = genpd_remove_device(pd, dev);
 		if (ret != -EAGAIN)
@@ -2635,9 +2641,10 @@  static void genpd_dev_pm_sync(struct device *dev)
 static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 				 unsigned int index, bool power_on)
 {
+	struct device_node *np;
 	struct of_phandle_args pd_args;
 	struct generic_pm_domain *pd;
-	int ret;
+	int ret, pstate;
 
 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
 				"#power-domain-cells", index, &pd_args);
@@ -2675,10 +2682,25 @@  static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 		genpd_unlock(pd);
 	}
 
-	if (ret)
+	if (ret) {
 		genpd_remove_device(pd, dev);
+		return -EPROBE_DEFER;
+	}
+
+	/* Set the default performance state */
+	np = base_dev->of_node;
+	if (of_parse_phandle(np, "required-opps", index)) {
+		pstate = of_get_required_opp_performance_state(np, index);
+		if (pstate < 0) {
+			ret = pstate;
+			dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
+				pd->name, ret);
+		}
+		dev_pm_genpd_set_performance_state(dev, pstate);
+		dev_gpd_data(dev)->default_pstate = pstate;
+	}
 
-	return ret ? -EPROBE_DEFER : 1;
+	return ret ? ret : 1;
 }
 
 /**
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 21a0577..67017c9 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -198,6 +198,7 @@  struct generic_pm_domain_data {
 	struct notifier_block *power_nb;
 	int cpu;
 	unsigned int performance_state;
+	unsigned int default_pstate;
 	unsigned int rpm_pstate;
 	ktime_t	next_wakeup;
 	void *data;