leds: fix multiple requests and releases of IRQ for GPIO LED Trigger (48cccd26) · Commits · 戴 / test

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>

drivers/leds/ledtrig-gpio.c

+14 −7

Original line number	Diff line number	Diff line
		@@ -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) {
		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;
		}
		@@ -211,6 +217,7 @@ 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);
		if (gpio_data->gpio != 0)
		free_irq(gpio_to_irq(gpio_data->gpio), led);
		kfree(gpio_data);
		}

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