media: adv7180: Use v4l2-ctrls core to handle s_ctrl locking

Instead of handling the state lock ourself in .s_ctrl use the v4l2-ctrls
core to handle it for us. This will allow us later to use the unlocked
__v4l2_ctrl_handler_setup() in initialization code where the state lock
is already held.

Add a lockdep assert to demonstrate the mutex must be held when setting
controls.

There is no functional change.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
index 9dbd33c4a30c086dbe7f2a781bd83846f63a6232..7b0387151c3a62061edbeaa217a13a549b55e7a2 100644 (file)
--- a/drivers/media/i2c/adv7180.c
+++ b/drivers/media/i2c/adv7180.c
@@ -601,11 +601,11 @@ static int adv7180_s_ctrl(struct v4l2_ctrl *ctrl)
 {
        struct v4l2_subdev *sd = to_adv7180_sd(ctrl);
        struct adv7180_state *state = to_state(sd);
-       int ret = mutex_lock_interruptible(&state->mutex);
+       int ret = 0;
        int val;
 
-       if (ret)
-               return ret;
+       lockdep_assert_held(&state->mutex);
+
        val = ctrl->val;
        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
@@ -647,7 +647,6 @@ static int adv7180_s_ctrl(struct v4l2_ctrl *ctrl)
                ret = -EINVAL;
        }
 
-       mutex_unlock(&state->mutex);
        return ret;
 }
 
@@ -668,6 +667,7 @@ static const struct v4l2_ctrl_config adv7180_ctrl_fast_switch = {
 static int adv7180_init_controls(struct adv7180_state *state)
 {
        v4l2_ctrl_handler_init(&state->ctrl_hdl, 4);
+       state->ctrl_hdl.lock = &state->mutex;
 
        v4l2_ctrl_new_std(&state->ctrl_hdl, &adv7180_ctrl_ops,
                          V4L2_CID_BRIGHTNESS, ADV7180_BRI_MIN,