linux-kernel - [PATCH v5 07/12] power: supply: smb347-charger: Make smb347_set

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Date:   Sat, 17 Jul 2021 21:21:29 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <treding@...dia.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mark Brown <broonie@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Sebastian Reichel <sre@...nel.org>,
        Peter Chen <peter.chen@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Felipe Balbi <balbi@...nel.org>,
        David Heidelberg <david@...t.cz>
Cc:     devicetree@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-tegra@...r.kernel.org
Subject: [PATCH v5 07/12] power: supply: smb347-charger: Make smb347_set_writable() IRQ-safe

The smb347_set_writable() is used by interrupt handler and outside of it.
The interrupt should be disabled when the function is used outside of
interrupt handler in order to prevent racing with the interrupt context.
Add new parameter to smb347_set_writable() that allows to disable IRQ.

Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/power/supply/smb347-charger.c | 30 +++++++++++++++++++--------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/power/supply/smb347-charger.c b/drivers/power/supply/smb347-charger.c
index df240420f2de..db1378b41f80 100644
--- a/drivers/power/supply/smb347-charger.c
+++ b/drivers/power/supply/smb347-charger.c
@@ -671,10 +671,22 @@ static int smb347_set_temp_limits(struct smb347_charger *smb)
  *
  * Returns %0 on success and negative errno in case of failure.
  */
-static int smb347_set_writable(struct smb347_charger *smb, bool writable)
+static int smb347_set_writable(struct smb347_charger *smb, bool writable,
+			       bool irq_toggle)
 {
-	return regmap_update_bits(smb->regmap, CMD_A, CMD_A_ALLOW_WRITE,
-				  writable ? CMD_A_ALLOW_WRITE : 0);
+	struct i2c_client *client = to_i2c_client(smb->dev);
+	int ret;
+
+	if (writable && irq_toggle && !smb->irq_unsupported)
+		disable_irq(client->irq);
+
+	ret = regmap_update_bits(smb->regmap, CMD_A, CMD_A_ALLOW_WRITE,
+				 writable ? CMD_A_ALLOW_WRITE : 0);
+
+	if ((!writable || ret) && irq_toggle && !smb->irq_unsupported)
+		enable_irq(client->irq);
+
+	return ret;
 }
 
 static int smb347_hw_init(struct smb347_charger *smb)
@@ -682,7 +694,7 @@ static int smb347_hw_init(struct smb347_charger *smb)
 	unsigned int val;
 	int ret;
 
-	ret = smb347_set_writable(smb, true);
+	ret = smb347_set_writable(smb, true, false);
 	if (ret < 0)
 		return ret;
 
@@ -758,7 +770,7 @@ static int smb347_hw_init(struct smb347_charger *smb)
 	ret = smb347_start_stop_charging(smb);
 
 fail:
-	smb347_set_writable(smb, false);
+	smb347_set_writable(smb, false, false);
 	return ret;
 }
 
@@ -866,7 +878,7 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
 	if (smb->irq_unsupported)
 		return 0;
 
-	ret = smb347_set_writable(smb, true);
+	ret = smb347_set_writable(smb, true, true);
 	if (ret < 0)
 		return ret;
 
@@ -891,7 +903,7 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
 	ret = regmap_update_bits(smb->regmap, CFG_PIN, CFG_PIN_EN_CHARGER_ERROR,
 				 enable ? CFG_PIN_EN_CHARGER_ERROR : 0);
 fail:
-	smb347_set_writable(smb, false);
+	smb347_set_writable(smb, false, true);
 	return ret;
 }
 
@@ -919,7 +931,7 @@ static int smb347_irq_init(struct smb347_charger *smb,
 	if (!client->irq)
 		return 0;
 
-	ret = smb347_set_writable(smb, true);
+	ret = smb347_set_writable(smb, true, false);
 	if (ret < 0)
 		return ret;
 
@@ -931,7 +943,7 @@ static int smb347_irq_init(struct smb347_charger *smb,
 				 CFG_STAT_ACTIVE_HIGH | CFG_STAT_DISABLED,
 				 CFG_STAT_DISABLED);
 
-	smb347_set_writable(smb, false);
+	smb347_set_writable(smb, false, false);
 
 	if (ret < 0) {
 		dev_warn(smb->dev, "failed to initialize IRQ: %d\n", ret);
-- 
2.32.0