gpio-charger: Fix potential race between irq handler and probe/remove

This patch fixes a potential race between the irq handler and the probe
and remove functions.

The irq should not be requested before the chargers power_supply has been
registered and has to be freed before the power_supply is unregistered,
otherwise it is possible that the irq fires while the power_supply is not
initialized yet or has already been freed.

While we are at it replace request_irq with request_any_context_irq.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 14 insertions, 15 deletions

diff --git a/drivers/power/gpio-charger.c b/drivers/power/gpio-charger.c
index 43078e34428a..25b88ac1d44c 100644
--- a/drivers/power/gpio-charger.c
+++ b/drivers/power/gpio-charger.c
@@ -98,7 +98,7 @@ static int __devinit gpio_charger_probe(struct platform_device *pdev)
         charger->type = pdata->type;
         charger->properties = gpio_charger_properties;
         charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
-        charger->get_property  = gpio_charger_get_property;
+        charger->get_property = gpio_charger_get_property;
         charger->supplied_to = pdata->supplied_to;
         charger->num_supplicants = pdata->num_supplicants;
 
@@ -113,9 +113,18 @@ static int __devinit gpio_charger_probe(struct platform_device *pdev)
                 goto err_gpio_free;
         }
 
+        gpio_charger->pdata = pdata;
+
+        ret = power_supply_register(&pdev->dev, charger);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to register power supply: %d\n",
+                        ret);
+                goto err_gpio_free;
+        }
+
         irq = gpio_to_irq(pdata->gpio);
         if (irq > 0) {
-                ret = request_irq(irq, gpio_charger_irq,
+                ret = request_any_context_irq(irq, gpio_charger_irq,
                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                                 dev_name(&pdev->dev), charger);
                 if (ret)
@@ -124,21 +133,10 @@ static int __devinit gpio_charger_probe(struct platform_device *pdev)
                         gpio_charger->irq = irq;
         }
 
-        gpio_charger->pdata = pdata;
-
-        ret = power_supply_register(&pdev->dev, charger);
-        if (ret < 0) {
-                dev_err(&pdev->dev, "Failed to register power supply: %d\n", ret);
-                goto err_irq_free;
-        }
-
         platform_set_drvdata(pdev, gpio_charger);
 
         return 0;
 
-err_irq_free:
-        if (gpio_charger->irq)
-                free_irq(gpio_charger->irq, charger);
 err_gpio_free:
         gpio_free(pdata->gpio);
 err_free:
@@ -150,10 +148,11 @@ static int __devexit gpio_charger_remove(struct platform_device *pdev)
 {
         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 
-        power_supply_unregister(&gpio_charger->charger);
-
         if (gpio_charger->irq)
                 free_irq(gpio_charger->irq, &gpio_charger->charger);
+
+        power_supply_unregister(&gpio_charger->charger);
+
         gpio_free(gpio_charger->pdata->gpio);
 
         platform_set_drvdata(pdev, NULL);