[PATCH] media: cdns-csi2rx: fix call balance for csi2rx->p_clk handling routines

[Vitalii Mordan]

If the clock csi2rx->p_clk was not enabled in csi2rx_stop(), it should not
be disabled in any path.

Conversely, if it was enabled in csi2rx_stop(), it must be disabled in all
error paths to ensure proper cleanup.

Found by Linux Verification Center (linuxtesting.org) with Klever.

Fixes: 1fc3b37f34f6 ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vitalii Mordan <mordan@xxxxxxxxx>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 4d64df829e75..e7e8decf9a02 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -322,11 +322,14 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
 
 static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 {
+	int ret, ret_clk;
 	unsigned int i;
 	u32 val;
-	int ret;
 
-	clk_prepare_enable(csi2rx->p_clk);
+	ret_clk = clk_prepare_enable(csi2rx->p_clk);
+	if (ret_clk)
+		dev_warn(csi2rx->dev,
+			 "Couldn't prepare and enable P clock\n");
 	reset_control_assert(csi2rx->sys_rst);
 	clk_disable_unprepare(csi2rx->sys_clk);
 
@@ -348,7 +351,8 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
 	}
 
 	reset_control_assert(csi2rx->p_rst);
-	clk_disable_unprepare(csi2rx->p_clk);
+	if (!ret_clk)
+		clk_disable_unprepare(csi2rx->p_clk);
 
 	if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
 		dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
-- 
2.25.1