[PATCH 1/2] OPP: Use opp_table->regulators to verify no regulator case

[PATCH 1/2] OPP: Use opp_table->regulators to verify no regulator case

[Viresh Kumar]

The value of opp_table->regulator_count is not very consistent right now
and it may end up being 0 while we do have a "opp-microvolt" property in
the OPP table. It was kept that way as we used to check if any
regulators are set with the OPP core for a device or not using value of
regulator_count.

Lets use opp_table->regulators for that purpose as the meaning of
regulator_count is going to change in the later patches.

Reported-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/opp/core.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 2c2df4e4fc14..2d3d0d1180ea 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -196,12 +196,12 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 	if (IS_ERR(opp_table))
 		return 0;
 
-	count = opp_table->regulator_count;
-
 	/* Regulator may not be required for the device */
-	if (!count)
+	if (!opp_table->regulators)
 		goto put_opp_table;
 
+	count = opp_table->regulator_count;
+
 	uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
 	if (!uV)
 		goto put_opp_table;
@@ -1049,6 +1049,9 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
 	struct regulator *reg;
 	int i;
 
+	if (!opp_table->regulators)
+		return true;
+
 	for (i = 0; i < opp_table->regulator_count; i++) {
 		reg = opp_table->regulators[i];
 
@@ -1333,7 +1336,7 @@ static int _allocate_set_opp_data(struct opp_table *opp_table)
 	struct dev_pm_set_opp_data *data;
 	int len, count = opp_table->regulator_count;
 
-	if (WARN_ON(!count))
+	if (WARN_ON(!opp_table->regulators))
 		return -EINVAL;
 
 	/* space for set_opp_data */
-- 
2.19.1.568.g152ad8e3369a

[PATCH 2/2] OPP: Fix missing debugfs supply directory for OPPs

[Viresh Kumar]

There is one case where we may end up with no "supply" directory for the
OPPs in debugfs. That happens when the OPP core isn't managing the
regulators for the device and the device's OPP do have microvolt
property. It happens because the opp_table->regulator_count remains set
to 0 and the debugfs routines don't add any supply directory in such a
case.

This commit fixes that by setting opp_table->regulator_count to 1 in
that particular case. But to make everything work nicely and not break
other parts of the core, regulator_count is defined as "int" now instead
of "unsigned int" and it can have different special values now. It is
set to -1 initially to mark it "uninitialized" and later only we set it
to 0 or positive values after checking how many supplies are there.

This also helps in finding the bugs where only few of the OPPs have the
"opp-microvolt" property set and not all.

Fixes: 1fae788ed640 ("PM / OPP: Don't create debugfs "supply-0" directory unnecessarily")
Reported-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/opp/core.c | 12 +++++++++---
 drivers/opp/of.c   | 20 ++++++++++++++++----
 drivers/opp/opp.h  |  6 ++++--
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 2d3d0d1180ea..23b086fcbf84 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -812,6 +812,9 @@ static struct opp_table *_allocate_opp_table(struct device *dev, int index)
 	mutex_init(&opp_table->lock);
 	INIT_LIST_HEAD(&opp_table->dev_list);
 
+	/* Mark regulator count uninitialized */
+	opp_table->regulator_count = -1;
+
 	opp_dev = _add_opp_dev(dev, opp_table);
 	if (!opp_dev) {
 		kfree(opp_table);
@@ -1028,7 +1031,7 @@ struct dev_pm_opp *_opp_allocate(struct opp_table *table)
 	int count, supply_size;
 
 	/* Allocate space for at least one supply */
-	count = table->regulator_count ? table->regulator_count : 1;
+	count = table->regulator_count > 0 ? table->regulator_count : 1;
 	supply_size = sizeof(*opp->supplies) * count;
 
 	/* allocate new OPP node and supplies structures */
@@ -1433,7 +1436,7 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
 
 	kfree(opp_table->regulators);
 	opp_table->regulators = NULL;
-	opp_table->regulator_count = 0;
+	opp_table->regulator_count = -1;
 err:
 	dev_pm_opp_put_opp_table(opp_table);
 
@@ -1462,7 +1465,7 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
 
 	kfree(opp_table->regulators);
 	opp_table->regulators = NULL;
-	opp_table->regulator_count = 0;
+	opp_table->regulator_count = -1;
 
 put_opp_table:
 	dev_pm_opp_put_opp_table(opp_table);
@@ -1615,6 +1618,9 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
 	if (!opp_table)
 		return -ENOMEM;
 
+	/* Fix regulator count for dynamic OPPs */
+	opp_table->regulator_count = 1;
+
 	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
 	if (ret)
 		dev_pm_opp_put_opp_table(opp_table);
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index 38a08805a30c..6eb0198ab63d 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -150,12 +150,10 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 			      struct opp_table *opp_table)
 {
 	u32 *microvolt, *microamp = NULL;
-	int supplies, vcount, icount, ret, i, j;
+	int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
 	struct property *prop = NULL;
 	char name[NAME_MAX];
 
-	supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
-
 	/* Search for "opp-microvolt-<name>" */
 	if (opp_table->prop_name) {
 		snprintf(name, sizeof(name), "opp-microvolt-%s",
@@ -170,7 +168,13 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 
 		/* Missing property isn't a problem, but an invalid entry is */
 		if (!prop) {
-			if (!opp_table->regulator_count)
+			if (unlikely(supplies == -1)) {
+				/* Initialize regulator_count */
+				opp_table->regulator_count = 0;
+				return 0;
+			}
+
+			if (!supplies)
 				return 0;
 
 			dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
@@ -179,6 +183,14 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
 		}
 	}
 
+	if (unlikely(supplies == -1)) {
+		/* Initialize regulator_count */
+		supplies = opp_table->regulator_count = 1;
+	} else if (unlikely(!supplies)) {
+		dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
+		return -EINVAL;
+	}
+
 	vcount = of_property_count_u32_elems(opp->np, name);
 	if (vcount < 0) {
 		dev_err(dev, "%s: Invalid %s property (%d)\n",
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index 9c6544b4f4f9..14d732ccad08 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -138,7 +138,9 @@ enum opp_table_access {
  * @prop_name: A name to postfix to many DT properties, while parsing them.
  * @clk: Device's clock handle
  * @regulators: Supply regulators
- * @regulator_count: Number of power supply regulators
+ * @regulator_count: Number of power supply regulators. Its value can be -1
+ * (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
+ * property).
  * @genpd_performance_state: Device's power domain support performance state.
  * @set_opp: Platform specific set_opp callback
  * @set_opp_data: Data to be passed to set_opp callback
@@ -176,7 +178,7 @@ struct opp_table {
 	const char *prop_name;
 	struct clk *clk;
 	struct regulator **regulators;
-	unsigned int regulator_count;
+	int regulator_count;
 	bool genpd_performance_state;
 
 	int (*set_opp)(struct dev_pm_set_opp_data *data);
-- 
2.19.1.568.g152ad8e3369a

Re: [PATCH 2/2] OPP: Fix missing debugfs supply directory for OPPs

[Quentin Perret]

On Tuesday 11 Dec 2018 at 16:56:29 (+0530), Viresh Kumar wrote:
> There is one case where we may end up with no "supply" directory for the
> OPPs in debugfs. That happens when the OPP core isn't managing the
> regulators for the device and the device's OPP do have microvolt
> property. It happens because the opp_table->regulator_count remains set
> to 0 and the debugfs routines don't add any supply directory in such a
> case.
> 
> This commit fixes that by setting opp_table->regulator_count to 1 in
> that particular case. But to make everything work nicely and not break
> other parts of the core, regulator_count is defined as "int" now instead
> of "unsigned int" and it can have different special values now. It is
> set to -1 initially to mark it "uninitialized" and later only we set it
> to 0 or positive values after checking how many supplies are there.
> 
> This also helps in finding the bugs where only few of the OPPs have the
> "opp-microvolt" property set and not all.

Tested on Juno r0 and Hikey960 successfully. The 'supply' directory is
now correctly exposed.

Feel free to add Tested-by: Quentin Perret <quentin.perret@arm.com>

Thanks,
Quentin

Re: [PATCH 2/2] OPP: Fix missing debugfs supply directory for OPPs

[Viresh Kumar]

On 11-12-18, 13:48, Quentin Perret wrote:
> On Tuesday 11 Dec 2018 at 16:56:29 (+0530), Viresh Kumar wrote:
> > There is one case where we may end up with no "supply" directory for the
> > OPPs in debugfs. That happens when the OPP core isn't managing the
> > regulators for the device and the device's OPP do have microvolt
> > property. It happens because the opp_table->regulator_count remains set
> > to 0 and the debugfs routines don't add any supply directory in such a
> > case.
> > 
> > This commit fixes that by setting opp_table->regulator_count to 1 in
> > that particular case. But to make everything work nicely and not break
> > other parts of the core, regulator_count is defined as "int" now instead
> > of "unsigned int" and it can have different special values now. It is
> > set to -1 initially to mark it "uninitialized" and later only we set it
> > to 0 or positive values after checking how many supplies are there.
> > 
> > This also helps in finding the bugs where only few of the OPPs have the
> > "opp-microvolt" property set and not all.
> 
> Tested on Juno r0 and Hikey960 successfully. The 'supply' directory is
> now correctly exposed.
> 
> Feel free to add Tested-by: Quentin Perret <quentin.perret@arm.com>

Thanks.

-- 
viresh