On Thu, 13 May 2021 15:07:44 +0300
Alexandru Ardelean <aardelean@xxxxxxxxxxx> wrote:
> This change fixes a corner-case, where for a zero regulator value, the
> driver would exit early, initializing the driver only partially.
> The driver would be in an unknown state.
>
> This change reworks the code to check regulator_voltage() return value
> for negative (error) first, and return early. This is the more common
> idiom.
>
> Also, this change is removing the 'voltage_uv' variable and using the 'ret'
> value directly. The only place where 'voltage_uv' is being used is to
> compute the internal reference voltage, and the type of this variable is
> 'int' (same are for 'ret'). Using only 'ret' avoids having to assign it on
> the error path.
>
> Fixes: ab0afa65bbc7 ("staging: iio: adc: ad7192: fail probe on get_voltage")
> Cc: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
> Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxx>
I've applied the first 4 patches to the fixes-togreg branch of iio.git and
cc'd stable.
Added note to the first 3 about the sign-off chain as its a bit unusual
for it to include loops ;) I always debate if I should sign-off again
when this happens, but decide against.
Jonathan
> ---
> drivers/iio/adc/ad7192.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
> index d3be67aa0522..1141cc13a124 100644
> --- a/drivers/iio/adc/ad7192.c
> +++ b/drivers/iio/adc/ad7192.c
> @@ -912,7 +912,7 @@ static int ad7192_probe(struct spi_device *spi)
> {
> struct ad7192_state *st;
> struct iio_dev *indio_dev;
> - int ret, voltage_uv = 0;
> + int ret;
>
> if (!spi->irq) {
> dev_err(&spi->dev, "no IRQ?\n");
> @@ -949,15 +949,12 @@ static int ad7192_probe(struct spi_device *spi)
> goto error_disable_avdd;
> }
>
> - voltage_uv = regulator_get_voltage(st->avdd);
> -
> - if (voltage_uv > 0) {
> - st->int_vref_mv = voltage_uv / 1000;
> - } else {
> - ret = voltage_uv;
> + ret = regulator_get_voltage(st->avdd);
> + if (ret < 0) {
> dev_err(&spi->dev, "Device tree error, reference voltage undefined\n");
> goto error_disable_avdd;
> }
> + st->int_vref_mv = ret / 1000;
>
> spi_set_drvdata(spi, indio_dev);
> st->chip_info = of_device_get_match_data(&spi->dev);
