Re: [PATCH v4 2/2] staging: iio: adc: ad7816: Use DMA-safe buffer for SPI read

[Joshua Crofts]

On Sun,  6 Sep 2026 14:40:49 +0300
Abdelnasser Hussein <abdelnasserhussein11@xxxxxxxxx> wrote:

> diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
> index ab80b3a889bb..e14ae805f076 100644
> --- a/drivers/staging/iio/adc/ad7816.c
> +++ b/drivers/staging/iio/adc/ad7816.c
> @@ -52,6 +52,8 @@ struct ad7816_chip_info {
>  	u8  oti_data[AD7816_CS_MAX + 1];
>  	u8  channel_id;	/* 0 always be temperature */
>  	u8  mode;
> +	struct mutex lock; /* protect device state during SPI transfers */

See my 2 replies to the previous patch. This change shouldn't be here.

> +	__be16 rx_buf __aligned(IIO_DMA_MINALIGN);
>  };
>  
>  enum ad7816_type {
> @@ -94,13 +96,13 @@ static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data)
>  
>  	gpiod_set_value(chip->rdwr_pin, 0);
>  	gpiod_set_value(chip->rdwr_pin, 1);
> -	ret = spi_read(spi_dev, &buf, sizeof(*data));

As well as the fact you removed buf in the first patch, causing build
errors.

-- 
Kind regards,
Joshua Crofts