From 902edc2a1c1ae4b514efd800dc5d5bc5b6d58991 Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Wed, 16 Jun 2021 14:46:04 +0200 Subject: [PATCH] media: i2c: max9286: Cache channel amplitude Cache the current channel amplitude in a driver variable to skip updating it if the newly requested value is the same as the currently configured one. Signed-off-by: Jacopo Mondi Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- 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 22021e9..5336862 100644 --- a/drivers/media/i2c/max9286.c +++ b/drivers/media/i2c/max9286.c @@ -165,6 +165,7 @@ struct max9286_priv { /* The initial reverse control channel amplitude. */ u32 init_rev_chan_mv; + u32 rev_chan_mv; struct v4l2_ctrl_handler ctrls; struct v4l2_ctrl *pixelrate; @@ -341,8 +342,15 @@ 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. @@ -564,8 +572,7 @@ 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); /* -- 2.7.4