[PATCH v2 1/3] media: i2c: ov5693: Program the mode registers on stream start

[Marco Ziliani <rylos78@gmail.com>]

ov5693_mode_configure() is only called from the runtime PM resume path,
through ov5693_sensor_init(). If the sensor stays powered between two
streams with different modes, the settings for the second mode are never
written to the hardware.

Move the call from ov5693_sensor_init() to ov5693_s_stream(), before the
controls are applied, so that the mode is written on every stream start.

Fixes: 89aef879cb53 ("media: i2c: Add support for ov5693 sensor")
Link: https://github.com/linux-surface/kernel/pull/181
Signed-off-by: Marco Ziliani <rylos78@gmail.com>
---
 drivers/media/i2c/ov5693.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/media/i2c/ov5693.c b/drivers/media/i2c/ov5693.c
index 56599f9ca..d09095c3e 100644
--- a/drivers/media/i2c/ov5693.c
+++ b/drivers/media/i2c/ov5693.c
@@ -663,11 +663,6 @@ static int ov5693_sensor_init(struct ov5693_device *ov5693)
 		return dev_err_probe(ov5693->dev, ret,
 				     "global settings error\n");
 
-	ret = ov5693_mode_configure(ov5693);
-	if (ret)
-		return dev_err_probe(ov5693->dev, ret,
-				     "mode configure error\n");
-
 	ret = ov5693_enable_streaming(ov5693, false);
 	if (ret)
 		dev_err(ov5693->dev, "stop streaming error\n");
@@ -1000,6 +995,19 @@ static int ov5693_s_stream(struct v4l2_subdev *sd, int enable)
 			return ret;
 
 		mutex_lock(&ov5693->lock);
+
+		/*
+		 * Program the mode on every stream start, so that a format
+		 * change also reaches a sensor that stayed powered since the
+		 * previous stream, and before the controls so that the mode
+		 * registers don't clobber them.
+		 */
+		ret = ov5693_mode_configure(ov5693);
+		if (ret) {
+			mutex_unlock(&ov5693->lock);
+			goto err_power_down;
+		}
+
 		ret = __v4l2_ctrl_handler_setup(&ov5693->ctrls.handler);
 		if (ret) {
 			mutex_unlock(&ov5693->lock);

-- 
2.56.0