[PATCH v3 13/15] media: mt9m114: Drop start-, stop-streaming sequence from initialize

[Hans de Goede <hansg@kernel.org>]

Drop the start-, stop-streaming sequence from initialize.

When streaming is started with a runtime-suspended sensor,
mt9m114_start_streaming() will runtime-resume the sensor which calls
mt9m114_initialize() immediately followed by calling
mt9m114_set_state(ENTER_CONFIG_CHANGE).

This results in the following state changes in quick succession:

mt9m114_set_state(ENTER_CONFIG_CHANGE) -> transitions to STREAMING
mt9m114_set_state(ENTER_SUSPEND)       -> transitions to SUSPENDED
mt9m114_set_state(ENTER_CONFIG_CHANGE) -> transitions to STREAMING

these quick state changes confuses the CSI receiver on atomisp devices
causing streaming to not work.

Drop the state changes from mt9m114_initialize() so that only
a single mt9m114_set_state(ENTER_CONFIG_CHANGE) call is made
when streaming is started with a runtime-suspend sensor.

This means that the sensor may have config changes pending when
mt9m114_runtime_suspend() gets called the first time after mt9m114_probe(),
when streaming was not started within the 1 second runtime-pm timeout.
Keep track of this and do the ENTER_CONFIG_CHANGE + ENTER suspend from
mt9m114_runtime_suspend() if necessary.

Signed-off-by: Hans de Goede <hansg@kernel.org>
---
 drivers/media/i2c/mt9m114.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/media/i2c/mt9m114.c b/drivers/media/i2c/mt9m114.c
index 1280d90cd411..ec5e9ce24d1c 100644
--- a/drivers/media/i2c/mt9m114.c
+++ b/drivers/media/i2c/mt9m114.c
@@ -389,6 +389,7 @@ struct mt9m114 {
 
 	unsigned int pixrate;
 	bool streaming;
+	bool config_change_pending;
 	u32 clk_freq;
 
 	/* Pixel Array */
@@ -781,14 +782,7 @@ static int mt9m114_initialize(struct mt9m114 *sensor)
 	if (ret < 0)
 		return ret;
 
-	ret = mt9m114_set_state(sensor, MT9M114_SYS_STATE_ENTER_CONFIG_CHANGE);
-	if (ret < 0)
-		return ret;
-
-	ret = mt9m114_set_state(sensor, MT9M114_SYS_STATE_ENTER_SUSPEND);
-	if (ret < 0)
-		return ret;
-
+	sensor->config_change_pending = true;
 	return 0;
 }
 
@@ -987,6 +981,7 @@ static int mt9m114_start_streaming(struct mt9m114 *sensor,
 	if (ret)
 		goto error;
 
+	sensor->config_change_pending = false;
 	sensor->streaming = true;
 
 	return 0;
@@ -2315,6 +2310,14 @@ static int __maybe_unused mt9m114_runtime_suspend(struct device *dev)
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct mt9m114 *sensor = ifp_to_mt9m114(sd);
 
+	if (sensor->config_change_pending) {
+		/* mt9m114_set_state() prints errors itself, no need to check */
+		mt9m114_set_state(sensor,
+				  MT9M114_SYS_STATE_ENTER_CONFIG_CHANGE);
+		mt9m114_set_state(sensor,
+				  MT9M114_SYS_STATE_ENTER_SUSPEND);
+	}
+
 	mt9m114_power_off(sensor);
 
 	return 0;
-- 
2.49.0