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Date:   Sun, 3 May 2020 09:58:35 +0100
From:   Jonathan Cameron <jic23@kernel.org>
To:     Mathieu Othacehe <m.othacehe@gmail.com>
Cc:     knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 1/5] iio: vcnl4000: Fix i2c swapped word reading.
Message-ID: <20200503095835.37a9bcf2@archlinux>
In-Reply-To: <20200427095559.16131-2-m.othacehe@gmail.com>
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        <20200427095559.16131-2-m.othacehe@gmail.com>
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On Mon, 27 Apr 2020 11:55:55 +0200
Mathieu Othacehe <m.othacehe@gmail.com> wrote:

> The bytes returned by the i2c reading need to be swapped
> unconditionally. Otherwise, on be16 platforms, an incorrect value will be
> returned.

Missing sign off so I can't apply.  Also, please add an appropriate fixes
tag.

Once that's fixed I'll probably be a bit naughty with this one and
mark it for stable, but take it for the next merge window. Bug has been
there a while without anyone noticing so I don't mind delaying fixing it
a little longer to make it easier to merge the rest of the series.

Thanks,

Jonathan

> ---
>  drivers/iio/light/vcnl4000.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> index 58e97462e803..e5f86bd00fb0 100644
> --- a/drivers/iio/light/vcnl4000.c
> +++ b/drivers/iio/light/vcnl4000.c
> @@ -219,7 +219,6 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
>  				u8 rdy_mask, u8 data_reg, int *val)
>  {
>  	int tries = 20;
> -	__be16 buf;
>  	int ret;
>  
>  	mutex_lock(&data->vcnl4000_lock);
> @@ -246,13 +245,12 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
>  		goto fail;
>  	}
>  
> -	ret = i2c_smbus_read_i2c_block_data(data->client,
> -		data_reg, sizeof(buf), (u8 *) &buf);
> +	ret = i2c_smbus_read_word_swapped(data->client, data_reg);
>  	if (ret < 0)
>  		goto fail;
>  
>  	mutex_unlock(&data->vcnl4000_lock);
> -	*val = be16_to_cpu(buf);
> +	*val = ret;
>  
>  	return 0;
>