Re: [PATCH] Proposal for meter ade* patches

[Alison Schofield <amsfield22@gmail.com>]

On Sat, Mar 25, 2017 at 01:15:00PM +0530, Gargi Sharma wrote:
> The driver needs to insure atomicity during frequency
> changes of bus and device. The iiodev->mlock as used
> was not doing that. Replace it with the drivers existing
> buffer lock and execute spi_write directly.
> 
> Signed-off-by: Gargi Sharma <gs051095@gmail.com>

Hi Gargi,

It's certainly a clean, simple patch!  It's good that you're 
running it by Sayli, Simran, and Arushi.  Some consensus that
this flavor of fix will work in their drivers would be good
before forwarding it on for 'official' review.

An RFC tag might have been appropriate here, but no worries
now.  It's only in our Outreachy tree.

alisons

> ---
>  drivers/staging/iio/meter/ade7754.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/iio/meter/ade7754.c b/drivers/staging/iio/meter/ade7754.c
> index c8d2d4c..48339e9a 100644
> --- a/drivers/staging/iio/meter/ade7754.c
> +++ b/drivers/staging/iio/meter/ade7754.c
> @@ -513,7 +513,7 @@ static ssize_t ade7754_write_frequency(struct device *dev,
>  	if (!val)
>  		return -EINVAL;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->buf_lock);
>  
>  	t = 26000 / val;
>  	if (t > 0)
> @@ -531,10 +531,13 @@ static ssize_t ade7754_write_frequency(struct device *dev,
>  	reg &= ~(3 << 3);
>  	reg |= t << 3;
>  
> -	ret = ade7754_spi_write_reg_8(dev, ADE7754_WAVMODE, reg);
> +	st->tx[0] = ADE7754_WRITE_REG(ADE7754_WAVMODE);
> +	st->tx[1] = reg;
> +
> +	ret = spi_write(st->us, st->tx, 2);
>  
>  out:
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->buf_lock);
>  
>  	return ret ? ret : len;
>  }
> -- 
> 2.7.4
>