On 7/28/20 3:30 AM, Dmitry Osipenko wrote:

27.07.2020 23:57, Sowjanya Komatineni пишет:

quoted

+	/*
+	 * TRM has incorrectly documented to wait for done status from
+	 * calibration logic after CSI interface power on.
+	 * As per the design, calibration results are latched and applied
+	 * to the pads only when the link is in LP11 state which will happen
+	 * during the sensor stream-on.
+	 * CSI subdev stream-on triggers start of MIPI pads calibration.
+	 * Wait for calibration to finish here after sensor subdev stream-on
+	 * and in case of sensor stream-on failure, cancel the calibration.
+	 */
  	subdev = on ? src_subdev : csi_subdev;
  	ret = v4l2_subdev_call(subdev, video, s_stream, on);
-	if (ret < 0 && ret != -ENOIOCTLCMD)
+	if (ret < 0 && ret != -ENOIOCTLCMD) {

I assume -ENOIOCTLCMD means that camera wasn't turned ON, so why
-ENOIOCTLCMD is special?

No -ENOIOCTLCMD mean subdev don't have s_stream ops

quoted

+		if (on && csi_chan->mipi)
+			tegra_mipi_cancel_calibration(csi_chan->mipi);
  		return ret;
+	}
+
+	if (on && csi_chan->mipi) {

Does finish_calibration() really need to be called for ret=-ENOIOCTLCMD?

Shouldn't it be cancel_calibration( for the -ENOIOCTLCMD?

start calibration happens during csi sensor streaming which happens 
prior to this point.

In case if sensor subdev does not have s_stream ops, then either 
finish/cancel calibration should happen to disable the clock.

quoted

+		ret = tegra_mipi_finish_calibration(csi_chan->mipi);
+		if (ret < 0)
+			dev_err(csi_chan->csi->dev,
+				"MIPI calibration failed: %d\n", ret);

Doesn't v4l2_subdev_call(OFF) need to be invoked here on error?

Not required as on error streaming fails and runtime PM will turn off 
power anyway.

Also we only did csi subdev s_stream on and during sensor subdev 
s_stream on fail, actual stream dont happen and on tegra side frame 
capture by HW happens only when kthreads run.

quoted

+		return ret;
+	}
  
  	return 0;
  }