media: atmel: properly get pm_runtime

There are several issues in the way the atmel driver handles
pm_runtime_get_sync():

- it doesn't check return codes;
- it doesn't properly decrement the usage_count on all places;
- it starts streaming even if pm_runtime_get_sync() fails.
- while it tries to get pm_runtime at the clock enable logic,
  it doesn't check if the operation was suceeded.

Replace all occurrences of it to use the new kAPI:
pm_runtime_resume_and_get(), which ensures that, if the
return code is not negative, the usage_count was incremented.

With that, add additional checks when this is called, in order
to ensure that errors will be properly addressed.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/media/platform/atmel/atmel-isi.c b/drivers/media/platform/atmel/atmel-isi.c
index e392b3efe363..5b1dd358f2e6 100644
--- a/drivers/media/platform/atmel/atmel-isi.c
+++ b/drivers/media/platform/atmel/atmel-isi.c
@@ -422,7 +422,9 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 	struct frame_buffer *buf, *node;
 	int ret;
 
-	pm_runtime_get_sync(isi->dev);
+	ret = pm_runtime_resume_and_get(isi->dev);
+	if (ret < 0)
+		return ret;
 
 	/* Enable stream on the sub device */
 	ret = v4l2_subdev_call(isi->entity.subdev, video, s_stream, 1);
@@ -782,9 +784,10 @@ static int isi_enum_frameintervals(struct file *file, void *fh,
 	return 0;
 }
 
-static void isi_camera_set_bus_param(struct atmel_isi *isi)
+static int isi_camera_set_bus_param(struct atmel_isi *isi)
 {
 	u32 cfg1 = 0;
+	int ret;
 
 	/* set bus param for ISI */
 	if (isi->pdata.hsync_act_low)
@@ -801,12 +804,16 @@ static void isi_camera_set_bus_param(struct atmel_isi *isi)
 	cfg1 |= ISI_CFG1_THMASK_BEATS_16;
 
 	/* Enable PM and peripheral clock before operate isi registers */
-	pm_runtime_get_sync(isi->dev);
+	ret = pm_runtime_resume_and_get(isi->dev);
+	if (ret < 0)
+		return ret;
 
 	isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
 	isi_writel(isi, ISI_CFG1, cfg1);
 
 	pm_runtime_put(isi->dev);
+
+	return 0;
 }
 
 /* -----------------------------------------------------------------------*/
@@ -1085,7 +1092,11 @@ static int isi_graph_notify_complete(struct v4l2_async_notifier *notifier)
 		dev_err(isi->dev, "No supported mediabus format found\n");
 		return ret;
 	}
-	isi_camera_set_bus_param(isi);
+	ret = isi_camera_set_bus_param(isi);
+	if (ret) {
+		dev_err(isi->dev, "Can't wake up device\n");
+		return ret;
+	}
 
 	ret = isi_set_default_fmt(isi);
 	if (ret) {