[PATCH] firmware: raspberrypi: Fix a leak in 'rpi_firmware_get()'

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.

Add the corresponding 'put_device()' in the normal and error handling
paths.

Fixes: 4e3d60656a72 ("ARM: bcm2835: Add the Raspberry Pi firmware driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Review carefully, management of reference counted resources is sometimes
tricky.

I also think that a 'put_device()' just after the 'platform_get_drvdata()'
call, and before the 'if (!fw)', could be enough, but I find the
proposed version more easy to follow.
---
 drivers/firmware/raspberrypi.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
index 250e01680742..4b8978b254f9 100644
--- a/drivers/firmware/raspberrypi.c
+++ b/drivers/firmware/raspberrypi.c
@@ -329,12 +329,18 @@ struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
 
 	fw = platform_get_drvdata(pdev);
 	if (!fw)
-		return NULL;
+		goto err_put_device;
 
 	if (!kref_get_unless_zero(&fw->consumers))
-		return NULL;
+		goto err_put_device;
+
+	put_device(&pdev->dev);
 
 	return fw;
+
+err_put_device:
+	put_device(&pdev->dev);
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(rpi_firmware_get);
 
-- 
2.30.2