From 48cccd26f36511ddb6aeca07485ecf2829683907 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Wed, 26 Aug 2009 14:29:31 -0700 Subject: [PATCH 1/1] leds: fix multiple requests and releases of IRQ for GPIO LED Trigger 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 Signed-off-by: Samuel R. C. Vale Cc: Richard Purdie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/leds/ledtrig-gpio.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/leds/ledtrig-gpio.c b/drivers/leds/ledtrig-gpio.c index a247ae63374f..8183b81fca84 100644 --- a/drivers/leds/ledtrig-gpio.c +++ b/drivers/leds/ledtrig-gpio.c @@ -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); } } -- 2.39.2