[PATCH 08/25] media: atmel: properly get pm_runtime

[Mauro Carvalho Chehab]

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 at kernel.org>
---
 drivers/media/platform/atmel/atmel-isc-base.c | 30 ++++++++++++++-----
 drivers/media/platform/atmel/atmel-isi.c      | 19 +++++++++---
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
index fe3ec8d0eaee..ce8e1351fa53 100644
--- a/drivers/media/platform/atmel/atmel-isc-base.c
+++ b/drivers/media/platform/atmel/atmel-isc-base.c
@@ -294,9 +294,13 @@ static int isc_wait_clk_stable(struct clk_hw *hw)
 static int isc_clk_prepare(struct clk_hw *hw)
 {
 	struct isc_clk *isc_clk = to_isc_clk(hw);
+	int ret;
 
-	if (isc_clk->id == ISC_ISPCK)
-		pm_runtime_get_sync(isc_clk->dev);
+	if (isc_clk->id == ISC_ISPCK) {
+		ret = pm_runtime_resume_and_get(isc_clk->dev);
+		if (ret < 0)
+			return ret;
+	}
 
 	return isc_wait_clk_stable(hw);
 }
@@ -353,9 +357,13 @@ static int isc_clk_is_enabled(struct clk_hw *hw)
 {
 	struct isc_clk *isc_clk = to_isc_clk(hw);
 	u32 status;
+	int ret;
 
-	if (isc_clk->id == ISC_ISPCK)
-		pm_runtime_get_sync(isc_clk->dev);
+	if (isc_clk->id == ISC_ISPCK) {
+		ret = pm_runtime_resume_and_get(isc_clk->dev);
+		if (ret < 0)
+			return 0;
+	}
 
 	regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
 
@@ -807,7 +815,12 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
 		goto err_start_stream;
 	}
 
-	pm_runtime_get_sync(isc->dev);
+	ret = pm_runtime_resume_and_get(isc->dev);
+	if (ret < 0) {
+		v4l2_err(&isc->v4l2_dev, "RPM resume failed in subdev %d\n",
+			 ret);
+		goto err_pm_get;
+	}
 
 	ret = isc_configure(isc);
 	if (unlikely(ret))
@@ -838,7 +851,7 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 err_configure:
 	pm_runtime_put_sync(isc->dev);
-
+err_pm_get:
 	v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
 
 err_start_stream:
@@ -1809,6 +1822,7 @@ static void isc_awb_work(struct work_struct *w)
 	u32 baysel;
 	unsigned long flags;
 	u32 min, max;
+	int ret;
 
 	/* streaming is not active anymore */
 	if (isc->stop)
@@ -1831,7 +1845,9 @@ static void isc_awb_work(struct work_struct *w)
 	ctrls->hist_id = hist_id;
 	baysel = isc->config.sd_format->cfa_baycfg << ISC_HIS_CFG_BAYSEL_SHIFT;
 
-	pm_runtime_get_sync(isc->dev);
+	ret = pm_runtime_resume_and_get(isc->dev);
+	if (ret < 0)
+		return;
 
 	/*
 	 * only update if we have all the required histograms and controls
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) {
-- 
2.30.2