media: imx: imx8mq-mipi_csi2: fix system resume

during system resume, interconnect bandwidth would currently be requested
even though the device is runtime suspended. This leaves the system in an
unbalanced state.

Fix that by only doing that in runtimem pm and splitting up runtime and
system suspend to be a more readable:
imx8mq_mipi_csi_pm_*() does the generic things called from system- and
runtime functions that each do specific things on top.

Fixes: f33fd8d7 ("media: imx: add a driver for i.MX8MQ mipi csi rx phy and controller")
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/staging/media/imx/imx8mq-mipi-csi2.c

@@ -693,7 +693,7 @@ static int imx8mq_mipi_csi_async_register(struct csi_state *state)
  * Suspend/resume
  */
 
-static int imx8mq_mipi_csi_pm_suspend(struct device *dev, bool runtime)
+static int imx8mq_mipi_csi_pm_suspend(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct csi_state *state = mipi_sd_to_csi2_state(sd);
@@ -705,36 +705,21 @@ static int imx8mq_mipi_csi_pm_suspend(struct device *dev, bool runtime)
 		imx8mq_mipi_csi_stop_stream(state);
 		imx8mq_mipi_csi_clk_disable(state);
 		state->state &= ~ST_POWERED;
-		if (!runtime)
-			state->state |= ST_SUSPENDED;
 	}
 
 	mutex_unlock(&state->lock);
 
-	ret = icc_set_bw(state->icc_path, 0, 0);
-	if (ret)
-		dev_err(dev, "icc_set_bw failed with %d\n", ret);
-
 	return ret ? -EAGAIN : 0;
 }
 
-static int imx8mq_mipi_csi_pm_resume(struct device *dev, bool runtime)
+static int imx8mq_mipi_csi_pm_resume(struct device *dev)
 {
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct csi_state *state = mipi_sd_to_csi2_state(sd);
 	int ret = 0;
 
-	ret = icc_set_bw(state->icc_path, 0, state->icc_path_bw);
-	if (ret) {
-		dev_err(dev, "icc_set_bw failed with %d\n", ret);
-		return ret;
-	}
-
 	mutex_lock(&state->lock);
 
-	if (!runtime && !(state->state & ST_SUSPENDED))
-		goto unlock;
-
 	if (!(state->state & ST_POWERED)) {
 		state->state |= ST_POWERED;
 		ret = imx8mq_mipi_csi_clk_enable(state);
@@ -755,22 +740,60 @@ static int imx8mq_mipi_csi_pm_resume(struct device *dev, bool runtime)
 
 static int __maybe_unused imx8mq_mipi_csi_suspend(struct device *dev)
 {
-	return imx8mq_mipi_csi_pm_suspend(dev, false);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_state *state = mipi_sd_to_csi2_state(sd);
+	int ret;
+
+	ret = imx8mq_mipi_csi_pm_suspend(dev);
+	if (ret)
+		return ret;
+
+	state->state |= ST_SUSPENDED;
+
+	return ret;
 }
 
 static int __maybe_unused imx8mq_mipi_csi_resume(struct device *dev)
 {
-	return imx8mq_mipi_csi_pm_resume(dev, false);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_state *state = mipi_sd_to_csi2_state(sd);
+
+	if (!(state->state & ST_SUSPENDED))
+		return 0;
+
+	return imx8mq_mipi_csi_pm_resume(dev);
 }
 
 static int __maybe_unused imx8mq_mipi_csi_runtime_suspend(struct device *dev)
 {
-	return imx8mq_mipi_csi_pm_suspend(dev, true);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_state *state = mipi_sd_to_csi2_state(sd);
+	int ret;
+
+	ret = imx8mq_mipi_csi_pm_suspend(dev);
+	if (ret)
+		return ret;
+
+	ret = icc_set_bw(state->icc_path, 0, 0);
+	if (ret)
+		dev_err(dev, "icc_set_bw failed with %d\n", ret);
+
+	return ret;
 }
 
 static int __maybe_unused imx8mq_mipi_csi_runtime_resume(struct device *dev)
 {
-	return imx8mq_mipi_csi_pm_resume(dev, true);
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct csi_state *state = mipi_sd_to_csi2_state(sd);
+	int ret;
+
+	ret = icc_set_bw(state->icc_path, 0, state->icc_path_bw);
+	if (ret) {
+		dev_err(dev, "icc_set_bw failed with %d\n", ret);
+		return ret;
+	}
+
+	return imx8mq_mipi_csi_pm_resume(dev);
 }
 
 static const struct dev_pm_ops imx8mq_mipi_csi_pm_ops = {
@@ -918,7 +941,7 @@ static int imx8mq_mipi_csi_probe(struct platform_device *pdev)
 	/* Enable runtime PM. */
 	pm_runtime_enable(dev);
 	if (!pm_runtime_enabled(dev)) {
-		ret = imx8mq_mipi_csi_pm_resume(dev, true);
+		ret = imx8mq_mipi_csi_runtime_resume(dev);
 		if (ret < 0)
 			goto icc;
 	}
@@ -931,7 +954,7 @@ static int imx8mq_mipi_csi_probe(struct platform_device *pdev)
 
 cleanup:
 	pm_runtime_disable(&pdev->dev);
-	imx8mq_mipi_csi_pm_suspend(&pdev->dev, true);
+	imx8mq_mipi_csi_runtime_suspend(&pdev->dev);
 
 	media_entity_cleanup(&state->sd.entity);
 	v4l2_async_nf_unregister(&state->notifier);
@@ -955,7 +978,7 @@ static int imx8mq_mipi_csi_remove(struct platform_device *pdev)
 	v4l2_async_unregister_subdev(&state->sd);
 
 	pm_runtime_disable(&pdev->dev);
-	imx8mq_mipi_csi_pm_suspend(&pdev->dev, true);
+	imx8mq_mipi_csi_runtime_suspend(&pdev->dev);
 	media_entity_cleanup(&state->sd.entity);
 	mutex_destroy(&state->lock);
 	pm_runtime_set_suspended(&pdev->dev);