Re: [PATCH v2] staging: iio: ad7816: Switch to the gpio descriptor interface

[Sasha Levin <sashal@kernel.org>]

On Wed, Oct 17, 2018 at 08:17:20PM +0530, Nishad Kamdar wrote:
>+	chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_IN);
>+	if (IS_ERR(chip->rdwr_pin)) {
>+		ret = PTR_ERR(chip->rdwr_pin);
>+		dev_err(&spi_dev->dev, "Failed to request rdwr GPIO: %d\n",
>+			ret);
> 		return ret;
> 	}
>-	gpio_direction_input(chip->rdwr_pin);
>-	ret = devm_gpio_request(&spi_dev->dev, chip->convert_pin,
>-				spi_get_device_id(spi_dev)->name);
>-	if (ret) {
>-		dev_err(&spi_dev->dev, "Fail to request convert gpio PIN %d.\n",
>-			chip->convert_pin);
>+	chip->convert_pin = devm_gpiod_get(&spi_dev->dev, "convert", GPIOD_IN);
>+	if (IS_ERR(chip->convert_pin)) {
>+		ret = PTR_ERR(chip->convert_pin);
>+		dev_err(&spi_dev->dev, "Failed to request convert GPIO: %d\n",
>+			ret);
> 		return ret;
> 	}
>-	gpio_direction_input(chip->convert_pin);
>-	ret = devm_gpio_request(&spi_dev->dev, chip->busy_pin,
>-				spi_get_device_id(spi_dev)->name);
>-	if (ret) {
>-		dev_err(&spi_dev->dev, "Fail to request busy gpio PIN %d.\n",
>-			chip->busy_pin);
>+	chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy", GPIOD_IN);
>+	if (IS_ERR(chip->busy_pin)) {
>+		ret = PTR_ERR(chip->busy_pin);
>+		dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
>+			ret);
> 		return ret;
> 	}

Hm, from what I can tell devm_gpio_request() is allocating some memory,
which makes this a series of 4 allocations.

What happens if the fourth allocation fails? Do we leak the first three?

--
Thanks,
Sasha