linux-kernel - [PATCH] i2c: fix missing pm_runtime_put_sync in i2c_device

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Date:   Thu, 30 Apr 2020 17:43:21 +0200
From:   Alain Volmat <alain.volmat@...com>
To:     <wsa@...-dreams.de>, <robh+dt@...nel.org>
CC:     <mark.rutland@....com>, <pierre-yves.mordret@...com>,
        <mcoquelin.stm32@...il.com>, <alexandre.torgue@...com>,
        <linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-stm32@...md-mailman.stormreply.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <fabrice.gasnier@...com>,
        <alain.volmat@...com>
Subject: [PATCH] i2c: fix missing pm_runtime_put_sync in i2c_device_probe

In case of the I2C client exposes the flag I2C_CLIENT_HOST_NOTIFY,
pm_runtime_get_sync is called in order to always keep active the
adapter. However later on, pm_runtime_put_sync is never called
within the function in case of an error. This commit add this
error handling.

Fixes: 72bfcee11cf8 ("i2c: Prevent runtime suspend of adapter when Host Notify is required")
Signed-off-by: Alain Volmat <alain.volmat@...com>
---
 drivers/i2c/i2c-core-base.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 139aea351ffb..2e4560671183 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -338,8 +338,10 @@ static int i2c_device_probe(struct device *dev)
 		} else if (ACPI_COMPANION(dev)) {
 			irq = i2c_acpi_get_irq(client);
 		}
-		if (irq == -EPROBE_DEFER)
-			return irq;
+		if (irq == -EPROBE_DEFER) {
+			status = irq;
+			goto put_sync_adapter;
+		}
 
 		if (irq < 0)
 			irq = 0;
@@ -353,15 +355,19 @@ static int i2c_device_probe(struct device *dev)
 	 */
 	if (!driver->id_table &&
 	    !i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
-	    !i2c_of_match_device(dev->driver->of_match_table, client))
-		return -ENODEV;
+	    !i2c_of_match_device(dev->driver->of_match_table, client)) {
+		status = -ENODEV;
+		goto put_sync_adapter;
+	}
 
 	if (client->flags & I2C_CLIENT_WAKE) {
 		int wakeirq;
 
 		wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
-		if (wakeirq == -EPROBE_DEFER)
-			return wakeirq;
+		if (wakeirq == -EPROBE_DEFER) {
+			status = wakeirq;
+			goto put_sync_adapter;
+		}
 
 		device_init_wakeup(&client->dev, true);
 
@@ -408,6 +414,10 @@ static int i2c_device_probe(struct device *dev)
 err_clear_wakeup_irq:
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
+put_sync_adapter:
+	if (client->flags & I2C_CLIENT_HOST_NOTIFY)
+		pm_runtime_put_sync(&client->adapter->dev);
+
 	return status;
 }
 
-- 
2.17.1