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leds: fix multiple requests and releases of IRQ for GPIO LED Trigger

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When setting the same GPIO number, multiple IRQ shared requests will be
done without freing the previous request.  It will also try to free a
failed request or an already freed IRQ if 0 was written to the gpio file.

All these oops and leaks were fixed with the following solution: keep the
previous allocated GPIO (if any) still allocated in case the new request
fails.  The alternative solution would desallocate the previous allocated
GPIO and set gpio as 0.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Samuel R. C. Vale <srcvale@holoscopio.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thadeu Lima de Souza Cascardo 2009-08-26 14:29:31 -07:00 committed by Linus Torvalds
parent bdf57de4e6
commit 48cccd26f3
1 changed files with 14 additions and 7 deletions
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21
drivers/leds/ledtrig-gpio.c
View file

@ -146,20 +146,26 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
return -EINVAL;
}
if (gpio_data->gpio == gpio)
return n;
if (!gpio) {
free_irq(gpio_to_irq(gpio_data->gpio), led);
if (gpio_data->gpio != 0)
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = 0;
return n;
}
if (gpio_data->gpio > 0 && gpio_data->gpio != gpio)
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = gpio;
ret = request_irq(gpio_to_irq(gpio), gpio_trig_irq,
IRQF_SHARED | IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
if (ret)
if (ret) {
dev_err(dev, "request_irq failed with error %d\n", ret);
} else {
if (gpio_data->gpio != 0)
free_irq(gpio_to_irq(gpio_data->gpio), led);
gpio_data->gpio = gpio;
}
return ret ? ret : n;
}
@ -211,7 +217,8 @@ static void gpio_trig_deactivate(struct led_classdev *led)
device_remove_file(led->dev, &dev_attr_inverted);
device_remove_file(led->dev, &dev_attr_desired_brightness);
flush_work(&gpio_data->work);
free_irq(gpio_to_irq(gpio_data->gpio),led);
if (gpio_data->gpio != 0)
free_irq(gpio_to_irq(gpio_data->gpio), led);
kfree(gpio_data);
}
}