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 <[email protected]>
---
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;
+ 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;
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
Hi,
Rajendra Nayak <[email protected]> writes:
> @@ -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;
nit: might want to keep one variable declaration per line here.
--
balbi
On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <[email protected]> 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 <[email protected]>
> ---
> 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
On 8/2/2021 6:29 PM, Ulf Hansson wrote:
> On Tue, 20 Jul 2021 at 09:12, Rajendra Nayak <[email protected]> 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 <[email protected]>
>> ---
>> 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
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 <[email protected]> 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 <[email protected]>
>>> ---
>>> 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
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
On Wed, 4 Aug 2021 at 13:08, Rajendra Nayak <[email protected]> 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 <[email protected]> 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 <[email protected]>
> >>> ---
> >>> 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
On 04-08-21, 13:39, Ulf Hansson wrote:
> 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.
Sure, np.
--
viresh