Re: [PATCH V2] iio: mxs-lradc: Remove useless check in read_raw

[Jonathan Cameron <jic23@kernel.org>]

On 07/03/2013 10:25 PM, Marek Vasut wrote:
> The removed check in the read_raw implementation was always true,
> therefore remove it. This also fixes a bug, by closely inspecting
> the code, one can notice the iio_validate_scan_mask_onehot() will
> always return 1 and therefore the subsequent condition will always
> succeed, therefore making the mxs_lradc_read_raw() function always
> return -EINVAL; .
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Fabio Estevam <fabio.estevam@freescale.com>
Applied to the fixes-togreg branch of iio.git.

Thanks,
> ---
>  drivers/staging/iio/adc/mxs-lradc.c |    7 -------
>  1 file changed, 7 deletions(-)
> 
> V2: Update the patch description, by discussion on the ML, we found
>     out this accidentally fixes a bug.
> 
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
> index d92c97a..c318eb6 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -234,7 +234,6 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>  {
>  	struct mxs_lradc *lradc = iio_priv(iio_dev);
>  	int ret;
> -	unsigned long mask;
>  
>  	if (m != IIO_CHAN_INFO_RAW)
>  		return -EINVAL;
> @@ -243,12 +242,6 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>  	if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>  		return -EINVAL;
>  
> -	/* Validate the channel if it doesn't intersect with reserved chans. */
> -	bitmap_set(&mask, chan->channel, 1);
> -	ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
> -	if (ret)
> -		return -EINVAL;
> -
>  	/*
>  	 * See if there is no buffered operation in progess. If there is, simply
>  	 * bail out. This can be improved to support both buffered and raw IO at
>