[PATCH AUTOSEL 4.14 015/109] OPP: Protect dev_list with opp_table lock

[PATCH AUTOSEL 4.14 015/109] OPP: Protect dev_list with opp_table lock

[Sasha Levin]

From: Viresh Kumar <viresh.kumar@linaro.org>

[ Upstream commit 3d2556992a878a2210d3be498416aee39e0c32aa ]

The dev_list needs to be protected with a lock, else we may have
simultaneous access (addition/removal) to it and that would be racy.
Extend scope of the opp_table lock to protect dev_list as well.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/base/power/opp/core.c | 21 +++++++++++++++++++--
 drivers/base/power/opp/cpu.c  |  2 ++
 drivers/base/power/opp/opp.h  |  2 +-
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index d5e7e8cc4f221..8100c87691497 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -49,9 +49,14 @@ static struct opp_device *_find_opp_dev(const struct device *dev,
 static struct opp_table *_find_opp_table_unlocked(struct device *dev)
 {
 	struct opp_table *opp_table;
+	bool found;
 
 	list_for_each_entry(opp_table, &opp_tables, node) {
-		if (_find_opp_dev(dev, opp_table)) {
+		mutex_lock(&opp_table->lock);
+		found = !!_find_opp_dev(dev, opp_table);
+		mutex_unlock(&opp_table->lock);
+
+		if (found) {
 			_get_opp_table_kref(opp_table);
 
 			return opp_table;
@@ -711,6 +716,8 @@ struct opp_device *_add_opp_dev(const struct device *dev,
 
 	/* Initialize opp-dev */
 	opp_dev->dev = dev;
+
+	mutex_lock(&opp_table->lock);
 	list_add(&opp_dev->node, &opp_table->dev_list);
 
 	/* Create debugfs entries for the opp_table */
@@ -718,6 +725,7 @@ struct opp_device *_add_opp_dev(const struct device *dev,
 	if (ret)
 		dev_err(dev, "%s: Failed to register opp debugfs (%d)\n",
 			__func__, ret);
+	mutex_unlock(&opp_table->lock);
 
 	return opp_dev;
 }
@@ -736,6 +744,7 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
 	if (!opp_table)
 		return NULL;
 
+	mutex_init(&opp_table->lock);
 	INIT_LIST_HEAD(&opp_table->dev_list);
 
 	opp_dev = _add_opp_dev(dev, opp_table);
@@ -757,7 +766,6 @@ static struct opp_table *_allocate_opp_table(struct device *dev)
 
 	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
 	INIT_LIST_HEAD(&opp_table->opp_list);
-	mutex_init(&opp_table->lock);
 	kref_init(&opp_table->kref);
 
 	/* Secure the device table modification */
@@ -799,6 +807,10 @@ static void _opp_table_kref_release(struct kref *kref)
 	if (!IS_ERR(opp_table->clk))
 		clk_put(opp_table->clk);
 
+	/*
+	 * No need to take opp_table->lock here as we are guaranteed that no
+	 * references to the OPP table are taken at this point.
+	 */
 	opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device,
 				   node);
 
@@ -1702,6 +1714,9 @@ void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev,
 {
 	struct dev_pm_opp *opp, *tmp;
 
+	/* Protect dev_list */
+	mutex_lock(&opp_table->lock);
+
 	/* Find if opp_table manages a single device */
 	if (list_is_singular(&opp_table->dev_list)) {
 		/* Free static OPPs */
@@ -1712,6 +1727,8 @@ void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev,
 	} else {
 		_remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
 	}
+
+	mutex_unlock(&opp_table->lock);
 }
 
 void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
diff --git a/drivers/base/power/opp/cpu.c b/drivers/base/power/opp/cpu.c
index 2d87bc1adf38b..66e406bd4d628 100644
--- a/drivers/base/power/opp/cpu.c
+++ b/drivers/base/power/opp/cpu.c
@@ -222,8 +222,10 @@ int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
 	cpumask_clear(cpumask);
 
 	if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
+		mutex_lock(&opp_table->lock);
 		list_for_each_entry(opp_dev, &opp_table->dev_list, node)
 			cpumask_set_cpu(opp_dev->dev->id, cpumask);
+		mutex_unlock(&opp_table->lock);
 	} else {
 		cpumask_set_cpu(cpu_dev->id, cpumask);
 	}
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 166eef9905995..0a206c6b90868 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -124,7 +124,7 @@ enum opp_table_access {
  * @dev_list:	list of devices that share these OPPs
  * @opp_list:	table of opps
  * @kref:	for reference count of the table.
- * @lock:	mutex protecting the opp_list.
+ * @lock:	mutex protecting the opp_list and dev_list.
  * @np:		struct device_node pointer for opp's DT node.
  * @clock_latency_ns_max: Max clock latency in nanoseconds.
  * @shared_opp: OPP is shared between multiple devices.
-- 
2.20.1

[PATCH AUTOSEL 4.14 017/109] power: supply: twl4030_charger: fix charging current out-of-bounds

[Sasha Levin]

From: Andreas Kemnade <andreas@kemnade.info>

[ Upstream commit 8314c212f995bc0d06b54ad02ef0ab4089781540 ]

the charging current uses unsigned int variables, if we step back
if the current is still low, we would run into negative which
means setting the target to a huge value.
Better add checks here.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/twl4030_charger.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
index 0cc12bfe7b020..d3cba954bab54 100644
--- a/drivers/power/supply/twl4030_charger.c
+++ b/drivers/power/supply/twl4030_charger.c
@@ -420,7 +420,8 @@ static void twl4030_current_worker(struct work_struct *data)
 
 	if (v < USB_MIN_VOLT) {
 		/* Back up and stop adjusting. */
-		bci->usb_cur -= USB_CUR_STEP;
+		if (bci->usb_cur >= USB_CUR_STEP)
+			bci->usb_cur -= USB_CUR_STEP;
 		bci->usb_cur_target = bci->usb_cur;
 	} else if (bci->usb_cur >= bci->usb_cur_target ||
 		   bci->usb_cur + USB_CUR_STEP > USB_MAX_CURRENT) {
-- 
2.20.1

[PATCH AUTOSEL 4.14 018/109] power: supply: twl4030_charger: disable eoc interrupt on linear charge

[Sasha Levin]

From: Andreas Kemnade <andreas@kemnade.info>

[ Upstream commit 079cdff3d0a09c5da10ae1be35def7a116776328 ]

This avoids getting woken up from suspend after power interruptions
when the bci wrongly thinks the battery is full just because
of input current going low because of low input power

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/twl4030_charger.c | 27 +++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
index d3cba954bab54..b20491016b1e4 100644
--- a/drivers/power/supply/twl4030_charger.c
+++ b/drivers/power/supply/twl4030_charger.c
@@ -440,6 +440,7 @@ static void twl4030_current_worker(struct work_struct *data)
 static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
 {
 	int ret;
+	u32 reg;
 
 	if (bci->usb_mode == CHARGE_OFF)
 		enable = false;
@@ -453,14 +454,38 @@ static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
 			bci->usb_enabled = 1;
 		}
 
-		if (bci->usb_mode == CHARGE_AUTO)
+		if (bci->usb_mode == CHARGE_AUTO) {
+			/* Enable interrupts now. */
+			reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_ICHGEOC |
+					TWL4030_TBATOR2 | TWL4030_TBATOR1 |
+					TWL4030_BATSTS);
+			ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
+				       TWL4030_INTERRUPTS_BCIIMR1A);
+			if (ret < 0) {
+				dev_err(bci->dev,
+					"failed to unmask interrupts: %d\n",
+					ret);
+				return ret;
+			}
 			/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
 			ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
+		}
 
 		/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
 		ret = twl4030_clear_set(TWL_MODULE_MAIN_CHARGE, 0,
 			TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
 		if (bci->usb_mode == CHARGE_LINEAR) {
+			/* Enable interrupts now. */
+			reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_TBATOR2 |
+					TWL4030_TBATOR1 | TWL4030_BATSTS);
+			ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
+				       TWL4030_INTERRUPTS_BCIIMR1A);
+			if (ret < 0) {
+				dev_err(bci->dev,
+					"failed to unmask interrupts: %d\n",
+					ret);
+				return ret;
+			}
 			twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC|TWL4030_CVENAC, 0);
 			/* Watch dog key: WOVF acknowledge */
 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x33,
-- 
2.20.1