diff mbox series

opp: Return genpd virtual devices from dev_pm_opp_attach_genpd()

Message ID 027985ce35873cd218298302a1408da06d48458b.1562565567.git.viresh.kumar@linaro.org
State Accepted
Commit 17a8f868ae3e85a173843b1ac65e744e8585bc5a
Headers show
Series opp: Return genpd virtual devices from dev_pm_opp_attach_genpd() | expand

Commit Message

Viresh Kumar July 8, 2019, 6 a.m. UTC
The cpufreq drivers don't need to do runtime PM operations on the
virtual devices returned by dev_pm_domain_attach_by_name() and so the
virtual devices weren't shared with the callers of
dev_pm_opp_attach_genpd() earlier.

But the IO device drivers would want to do that. This patch updates the
prototype of dev_pm_opp_attach_genpd() to accept another argument to
return the pointer to the array of genpd virtual devices.

Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
@Rajendra: Can you please test this one ? I have only compile tested it.

 drivers/opp/core.c     | 5 ++++-
 include/linux/pm_opp.h | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b

Comments

Rajendra Nayak July 11, 2019, 9:39 a.m. UTC | #1
On 7/8/2019 11:30 AM, Viresh Kumar wrote:
> The cpufreq drivers don't need to do runtime PM operations on the

> virtual devices returned by dev_pm_domain_attach_by_name() and so the

> virtual devices weren't shared with the callers of

> dev_pm_opp_attach_genpd() earlier.

> 

> But the IO device drivers would want to do that. This patch updates the

> prototype of dev_pm_opp_attach_genpd() to accept another argument to

> return the pointer to the array of genpd virtual devices.

> 

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

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> ---

> @Rajendra: Can you please test this one ? I have only compile tested it.


Sorry for the delay, I seem to have completely missed this patch.
I just gave this a try and here are some observations,

I have a case where I have one device with 2 power domains, one of them
is scale-able (supports perf state) and the other one supports only being
turned on and off.

1. In the driver I now need to use dev_pm_domain_attach_by_name/id to attach the
power domain which supports only on/off and then use dev_pm_opp_attach_genpd()
for the one which supports perf states.

2. My OPP table has only 1 required_opps, so the required_opp_count for the OPP table is 1.
Now if my device tree has my scale-able powerdomain at index 1 (it works if its at index 0)
then I end up with this error

[    2.858628] ufshcd-qcom 1d84000.ufshc: Index can't be greater than required-opp-count - 1, rpmh_pd (1 : 1)

so it looks like a lot of the OPP core today just assumes that if a device has multiple power domains,
all of them are scale-able which isn't necessarily true.

> 

>   drivers/opp/core.c     | 5 ++++-

>   include/linux/pm_opp.h | 4 ++--

>   2 files changed, 6 insertions(+), 3 deletions(-)

> 

> diff --git a/drivers/opp/core.c b/drivers/opp/core.c

> index 2958cc7bbb58..07b6f1187b3b 100644

> --- a/drivers/opp/core.c

> +++ b/drivers/opp/core.c

> @@ -1775,6 +1775,7 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

>    * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer

>    * @dev: Consumer device for which the genpd is getting attached.

>    * @names: Null terminated array of pointers containing names of genpd to attach.

> + * @virt_devs: Pointer to return the array of virtual devices.

>    *

>    * Multiple generic power domains for a device are supported with the help of

>    * virtual genpd devices, which are created for each consumer device - genpd

> @@ -1789,7 +1790,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

>    * This helper needs to be called once with a list of all genpd to attach.

>    * Otherwise the original device structure will be used instead by the OPP core.

>    */

> -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)

> +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,

> +		const char **names, struct device ***virt_devs)

>   {

>   	struct opp_table *opp_table;

>   	struct device *virt_dev;

> @@ -1850,6 +1852,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names

>   		name++;

>   	}

>   

> +	*virt_devs = opp_table->genpd_virt_devs;

>   	mutex_unlock(&opp_table->genpd_virt_dev_lock);

>   

>   	return opp_table;

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

> index be570761b77a..7c2fe2952f40 100644

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

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

> @@ -131,7 +131,7 @@ struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char * name);

>   void dev_pm_opp_put_clkname(struct opp_table *opp_table);

>   struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*set_opp)(struct dev_pm_set_opp_data *data));

>   void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table);

> -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names);

> +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);

>   void dev_pm_opp_detach_genpd(struct opp_table *opp_table);

>   int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);

>   int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);

> @@ -295,7 +295,7 @@ static inline struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const

>   

>   static inline void dev_pm_opp_put_clkname(struct opp_table *opp_table) {}

>   

> -static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)

> +static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs)

>   {

>   	return ERR_PTR(-ENOTSUPP);

>   }

> 


-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
Niklas Cassel July 16, 2019, 10:43 a.m. UTC | #2
On Mon, Jul 08, 2019 at 11:30:11AM +0530, Viresh Kumar wrote:
> The cpufreq drivers don't need to do runtime PM operations on the

> virtual devices returned by dev_pm_domain_attach_by_name() and so the

> virtual devices weren't shared with the callers of

> dev_pm_opp_attach_genpd() earlier.

> 

> But the IO device drivers would want to do that. This patch updates the

> prototype of dev_pm_opp_attach_genpd() to accept another argument to

> return the pointer to the array of genpd virtual devices.

> 

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

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> ---

> @Rajendra: Can you please test this one ? I have only compile tested it.

> 

>  drivers/opp/core.c     | 5 ++++-

>  include/linux/pm_opp.h | 4 ++--

>  2 files changed, 6 insertions(+), 3 deletions(-)

> 

> diff --git a/drivers/opp/core.c b/drivers/opp/core.c

> index 2958cc7bbb58..07b6f1187b3b 100644

> --- a/drivers/opp/core.c

> +++ b/drivers/opp/core.c

> @@ -1775,6 +1775,7 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

>   * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer

>   * @dev: Consumer device for which the genpd is getting attached.

>   * @names: Null terminated array of pointers containing names of genpd to attach.

> + * @virt_devs: Pointer to return the array of virtual devices.

>   *

>   * Multiple generic power domains for a device are supported with the help of

>   * virtual genpd devices, which are created for each consumer device - genpd

> @@ -1789,7 +1790,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

>   * This helper needs to be called once with a list of all genpd to attach.

>   * Otherwise the original device structure will be used instead by the OPP core.

>   */

> -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)

> +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,

> +		const char **names, struct device ***virt_devs)

>  {

>  	struct opp_table *opp_table;

>  	struct device *virt_dev;

> @@ -1850,6 +1852,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names

>  		name++;

>  	}

>  

> +	*virt_devs = opp_table->genpd_virt_devs;


Could we perhaps only do this if (virt_devs), that way callers can send in
NULL if they don't care about the genpd virtual devices.

Kind regards,
Niklas

>  	mutex_unlock(&opp_table->genpd_virt_dev_lock);

>  

>  	return opp_table;

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

> index be570761b77a..7c2fe2952f40 100644

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

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

> @@ -131,7 +131,7 @@ struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char * name);

>  void dev_pm_opp_put_clkname(struct opp_table *opp_table);

>  struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*set_opp)(struct dev_pm_set_opp_data *data));

>  void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table);

> -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names);

> +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);

>  void dev_pm_opp_detach_genpd(struct opp_table *opp_table);

>  int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);

>  int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);

> @@ -295,7 +295,7 @@ static inline struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const

>  

>  static inline void dev_pm_opp_put_clkname(struct opp_table *opp_table) {}

>  

> -static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)

> +static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs)

>  {

>  	return ERR_PTR(-ENOTSUPP);

>  }

> -- 

> 2.21.0.rc0.269.g1a574e7a288b

>
Viresh Kumar July 17, 2019, 2:52 a.m. UTC | #3
On 16-07-19, 12:43, Niklas Cassel wrote:
> On Mon, Jul 08, 2019 at 11:30:11AM +0530, Viresh Kumar wrote:

> > The cpufreq drivers don't need to do runtime PM operations on the

> > virtual devices returned by dev_pm_domain_attach_by_name() and so the

> > virtual devices weren't shared with the callers of

> > dev_pm_opp_attach_genpd() earlier.

> > 

> > But the IO device drivers would want to do that. This patch updates the

> > prototype of dev_pm_opp_attach_genpd() to accept another argument to

> > return the pointer to the array of genpd virtual devices.

> > 

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

> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> > ---

> > @Rajendra: Can you please test this one ? I have only compile tested it.

> > 

> >  drivers/opp/core.c     | 5 ++++-

> >  include/linux/pm_opp.h | 4 ++--

> >  2 files changed, 6 insertions(+), 3 deletions(-)

> > 

> > diff --git a/drivers/opp/core.c b/drivers/opp/core.c

> > index 2958cc7bbb58..07b6f1187b3b 100644

> > --- a/drivers/opp/core.c

> > +++ b/drivers/opp/core.c

> > @@ -1775,6 +1775,7 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

> >   * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer

> >   * @dev: Consumer device for which the genpd is getting attached.

> >   * @names: Null terminated array of pointers containing names of genpd to attach.

> > + * @virt_devs: Pointer to return the array of virtual devices.

> >   *

> >   * Multiple generic power domains for a device are supported with the help of

> >   * virtual genpd devices, which are created for each consumer device - genpd

> > @@ -1789,7 +1790,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)

> >   * This helper needs to be called once with a list of all genpd to attach.

> >   * Otherwise the original device structure will be used instead by the OPP core.

> >   */

> > -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)

> > +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,

> > +		const char **names, struct device ***virt_devs)

> >  {

> >  	struct opp_table *opp_table;

> >  	struct device *virt_dev;

> > @@ -1850,6 +1852,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names

> >  		name++;

> >  	}

> >  

> > +	*virt_devs = opp_table->genpd_virt_devs;

> 

> Could we perhaps only do this if (virt_devs), that way callers can send in

> NULL if they don't care about the genpd virtual devices.


That was the idea and I failed to add it :(

-- 
viresh
Viresh Kumar July 17, 2019, 5:47 a.m. UTC | #4
On 11-07-19, 15:09, Rajendra Nayak wrote:
> Sorry for the delay


Same here :)

> I seem to have completely missed this patch.

> I just gave this a try and here are some observations,

> 

> I have a case where I have one device with 2 power domains, one of them

> is scale-able (supports perf state) and the other one supports only being

> turned on and off.

> 

> 1. In the driver I now need to use dev_pm_domain_attach_by_name/id to attach the

> power domain which supports only on/off and then use dev_pm_opp_attach_genpd()

> for the one which supports perf states.

> 

> 2. My OPP table has only 1 required_opps, so the required_opp_count for the OPP table is 1.

> Now if my device tree has my scale-able powerdomain at index 1 (it works if its at index 0)

> then I end up with this error

> 

> [    2.858628] ufshcd-qcom 1d84000.ufshc: Index can't be greater than required-opp-count - 1, rpmh_pd (1 : 1)

> 

> so it looks like a lot of the OPP core today just assumes that if a device has multiple power domains,

> all of them are scale-able which isn't necessarily true.


I don't think a lot of OPP core has these problems, but maybe only
this place. I was taking care of this since the beginning just forgot
it now.

What about this over this commit:

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index d76ead4eff4c..1f11f8c92337 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1789,13 +1789,16 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
  *
  * This helper needs to be called once with a list of all genpd to attach.
  * Otherwise the original device structure will be used instead by the OPP core.
+ *
+ * The order of entries in the names array must match the order in which
+ * "required-opps" are added in DT.
  */
 struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
                const char **names, struct device ***virt_devs)
 {
        struct opp_table *opp_table;
        struct device *virt_dev;
-       int index, ret = -EINVAL;
+       int index = 0, ret = -EINVAL;
        const char **name = names;
 
        opp_table = dev_pm_opp_get_opp_table(dev);
@@ -1821,14 +1824,6 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
                goto unlock;
 
        while (*name) {
-               index = of_property_match_string(dev->of_node,
-                                                "power-domain-names", *name);
-               if (index < 0) {
-                       dev_err(dev, "Failed to find power domain: %s (%d)\n",
-                               *name, index);
-                       goto err;
-               }
-
                if (index >= opp_table->required_opp_count) {
                        dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
                                *name, opp_table->required_opp_count, index);
@@ -1849,6 +1844,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
                }
 
                opp_table->genpd_virt_devs[index] = virt_dev;
+               index++;
                name++;
        }
 

-- 
viresh
Viresh Kumar July 17, 2019, 10:14 a.m. UTC | #5
On 17-07-19, 15:34, Rajendra Nayak wrote:
> 

> 

> On 7/17/2019 11:17 AM, Viresh Kumar wrote:

> > On 11-07-19, 15:09, Rajendra Nayak wrote:

> > > Sorry for the delay

> > 

> > Same here :)

> > 

> > > I seem to have completely missed this patch.

> > > I just gave this a try and here are some observations,

> > > 

> > > I have a case where I have one device with 2 power domains, one of them

> > > is scale-able (supports perf state) and the other one supports only being

> > > turned on and off.

> > > 

> > > 1. In the driver I now need to use dev_pm_domain_attach_by_name/id to attach the

> > > power domain which supports only on/off and then use dev_pm_opp_attach_genpd()

> > > for the one which supports perf states.

> > > 

> > > 2. My OPP table has only 1 required_opps, so the required_opp_count for the OPP table is 1.

> > > Now if my device tree has my scale-able powerdomain at index 1 (it works if its at index 0)

> > > then I end up with this error

> > > 

> > > [    2.858628] ufshcd-qcom 1d84000.ufshc: Index can't be greater than required-opp-count - 1, rpmh_pd (1 : 1)

> > > 

> > > so it looks like a lot of the OPP core today just assumes that if a device has multiple power domains,

> > > all of them are scale-able which isn't necessarily true.

> > 

> > I don't think a lot of OPP core has these problems, but maybe only

> > this place. I was taking care of this since the beginning just forgot

> > it now.

> > 

> > What about this over this commit:

> 

> Yes, this does seem to fix my concern mentioned in 2. above.


Great. I will include your Tested-by:, Lemme know if you have any
objections.

-- 
viresh
diff mbox series

Patch

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 2958cc7bbb58..07b6f1187b3b 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1775,6 +1775,7 @@  static void _opp_detach_genpd(struct opp_table *opp_table)
  * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
  * @dev: Consumer device for which the genpd is getting attached.
  * @names: Null terminated array of pointers containing names of genpd to attach.
+ * @virt_devs: Pointer to return the array of virtual devices.
  *
  * Multiple generic power domains for a device are supported with the help of
  * virtual genpd devices, which are created for each consumer device - genpd
@@ -1789,7 +1790,8 @@  static void _opp_detach_genpd(struct opp_table *opp_table)
  * This helper needs to be called once with a list of all genpd to attach.
  * Otherwise the original device structure will be used instead by the OPP core.
  */
-struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)
+struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
+		const char **names, struct device ***virt_devs)
 {
 	struct opp_table *opp_table;
 	struct device *virt_dev;
@@ -1850,6 +1852,7 @@  struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		name++;
 	}
 
+	*virt_devs = opp_table->genpd_virt_devs;
 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
 
 	return opp_table;
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index be570761b77a..7c2fe2952f40 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -131,7 +131,7 @@  struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char * name);
 void dev_pm_opp_put_clkname(struct opp_table *opp_table);
 struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev, int (*set_opp)(struct dev_pm_set_opp_data *data));
 void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table);
-struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names);
+struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);
 void dev_pm_opp_detach_genpd(struct opp_table *opp_table);
 int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);
 int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);
@@ -295,7 +295,7 @@  static inline struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const
 
 static inline void dev_pm_opp_put_clkname(struct opp_table *opp_table) {}
 
-static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)
+static inline struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs)
 {
 	return ERR_PTR(-ENOTSUPP);
 }