On 16/02/2021 17:41, Jacopo Mondi wrote:
> Cache the current channel amplitude in a driver variable
> to skip updating it if the new requested value is the same
> as the currently configured one.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
I like this model better than deciding outside of the call :-)
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/max9286.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index 1f14cd817fbf..4afb5ca06448 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -164,6 +164,7 @@ struct max9286_priv {
> bool mux_open;
>
> u32 init_rev_chan_mv;
> + u32 rev_chan_mv;
>
> struct v4l2_ctrl_handler ctrls;
> struct v4l2_ctrl *pixelrate;
> @@ -340,8 +341,15 @@ static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
> static void max9286_reverse_channel_setup(struct max9286_priv *priv,
> unsigned int chan_amplitude)
> {
> + u8 chan_config;
> +
> + if (priv->rev_chan_mv == chan_amplitude)
> + return;
> +
> + priv->rev_chan_mv = chan_amplitude;
> +
> /* Reverse channel transmission time: default to 1. */
> - u8 chan_config = MAX9286_REV_TRF(1);
> + chan_config = MAX9286_REV_TRF(1);
>
> /*
> * Reverse channel setup.
> @@ -563,8 +571,7 @@ static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
> * - Disable auto-ack as communication on the control channel are now
> * stable.
> */
> - if (priv->init_rev_chan_mv < 170)
> - max9286_reverse_channel_setup(priv, 170);
> + max9286_reverse_channel_setup(priv, 170);
> max9286_check_config_link(priv, priv->source_mask);
>
> /*
>
