Re: [PATCH 1/2] adv7180: fix field type to V4L2_FIELD_ALTERNATE

[Hans Verkuil <hverkuil@xs4all.nl>]

On 17/07/18 14:30, Niklas Söderlund wrote:
> The ADV7180 and ADV7182 transmit whole fields, bottom field followed
> by top (or vice-versa, depending on detected video standard). So
> for chips that do not have support for explicitly setting the field
> mode via I2P, set the field mode to V4L2_FIELD_ALTERNATE.

What does I2P do? I know it was explained before, but that's a long time
ago :-)

In any case, it should be explained in the commit log as well.

I faintly remember that it was just line-doubling of each field, in which
case this code seems correct.

Have you checked other drivers that use this subdev? Are they affected by
this change?

Regards,

	Hans

> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/media/i2c/adv7180.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
> index 25d24a3f10a7cb4d..c2e24132e8c21d38 100644
> --- a/drivers/media/i2c/adv7180.c
> +++ b/drivers/media/i2c/adv7180.c
> @@ -644,6 +644,9 @@ static int adv7180_mbus_fmt(struct v4l2_subdev *sd,
>  	fmt->width = 720;
>  	fmt->height = state->curr_norm & V4L2_STD_525_60 ? 480 : 576;
>  
> +	if (state->field == V4L2_FIELD_ALTERNATE)
> +		fmt->height /= 2;
> +
>  	return 0;
>  }
>  
> @@ -711,11 +714,11 @@ static int adv7180_set_pad_format(struct v4l2_subdev *sd,
>  
>  	switch (format->format.field) {
>  	case V4L2_FIELD_NONE:
> -		if (!(state->chip_info->flags & ADV7180_FLAG_I2P))
> -			format->format.field = V4L2_FIELD_INTERLACED;
> -		break;
> +		if (state->chip_info->flags & ADV7180_FLAG_I2P)
> +			break;
> +		/* fall through */
>  	default:
> -		format->format.field = V4L2_FIELD_INTERLACED;
> +		format->format.field = V4L2_FIELD_ALTERNATE;
>  		break;
>  	}
>  
> @@ -1291,7 +1294,7 @@ static int adv7180_probe(struct i2c_client *client,
>  		return -ENOMEM;
>  
>  	state->client = client;
> -	state->field = V4L2_FIELD_INTERLACED;
> +	state->field = V4L2_FIELD_ALTERNATE;
>  	state->chip_info = (struct adv7180_chip_info *)id->driver_data;
>  
>  	state->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
>