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, 23 insertions, 7 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