[PATCH 1/2] opp: Not all power-domains are scalable

[PATCH 1/2] opp: Not all power-domains are scalable

[Viresh Kumar]

A device may have multiple power-domains and not all of them may be
scalable (i.e. support performance states). But
dev_pm_opp_attach_genpd() doesn't take that into account currently.

Fix that by not verifying the names argument with "power-domain-names"
DT property and finding the index into the required-opps array. The
names argument will anyway get verified later on when we call
dev_pm_domain_attach_by_name().

Fixes: 6319aee10e53 ("opp: Attach genpds to devices from within OPP core")
Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/opp/core.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 2958cc7bbb58..4e2a81698cd2 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1788,12 +1788,15 @@ 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 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);
@@ -1819,14 +1822,6 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		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);
@@ -1847,6 +1842,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		}
 
 		opp_table->genpd_virt_devs[index] = virt_dev;
+		index++;
 		name++;
 	}
 
-- 
2.21.0.rc0.269.g1a574e7a288b

[PATCH V2 2/2] opp: Return genpd virtual devices from dev_pm_opp_attach_genpd()

[Viresh Kumar]

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>
Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V1->V2:
- Check virt_devs pointer before assigning.

 drivers/opp/core.c     | 6 +++++-
 include/linux/pm_opp.h | 4 ++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 4e2a81698cd2..1f11f8c92337 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
@@ -1792,7 +1793,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
  * 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 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;
@@ -1846,6 +1848,8 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
 		name++;
 	}
 
+	if (virt_devs)
+		*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);
 }
-- 
2.21.0.rc0.269.g1a574e7a288b