2018-06-12 17:26:33

by Nicholas Mc Guire

Subject: [PATCH] media: stm32-dcmi: simplify of_node_put usage

This does not fix any bug - this is just a code simplification. As
np is not used after passing it to v4l2_fwnode_endpoint_parse() its
refcount can be decremented immediately and at one location.

Signed-off-by: Nicholas Mc Guire <[email protected]>
---

Issue found during code reading.

Patch was compile tested with: x86_64_defconfig, MEDIA_SUPPORT=y
MEDIA_CAMERA_SUPPORT=y, V4L_PLATFORM_DRIVERS=y, OF=y, COMPILE_TEST=y
CONFIG_VIDEO_STM32_DCMI=y
(There are a few sparse warnings - but unrelated to the lines changed)

Patch is against 4.17.0 (localversion-next is next-20180608)

drivers/media/platform/stm32/stm32-dcmi.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 2e1933d..0b61042 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -1696,23 +1696,20 @@ static int dcmi_probe(struct platform_device *pdev)
}

ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(np), &ep);
+ of_node_put(np);
if (ret) {
dev_err(&pdev->dev, "Could not parse the endpoint\n");
- of_node_put(np);
return -ENODEV;
}

if (ep.bus_type == V4L2_MBUS_CSI2) {
dev_err(&pdev->dev, "CSI bus not supported\n");
- of_node_put(np);
return -ENODEV;
}
dcmi->bus.flags = ep.bus.parallel.flags;
dcmi->bus.bus_width = ep.bus.parallel.bus_width;
dcmi->bus.data_shift = ep.bus.parallel.data_shift;

- of_node_put(np);
-
irq = platform_get_irq(pdev, 0);
if (irq <= 0) {
dev_err(&pdev->dev, "Could not get irq\n");
--
2.1.4

2018-06-18 09:39:13

by Hugues Fruchet

Subject: Re: [PATCH] media: stm32-dcmi: simplify of_node_put usage

Hi Nicholas,
Thanks for patch,

On 06/12/2018 07:23 PM, Nicholas Mc Guire wrote:
> This does not fix any bug - this is just a code simplification. As
> np is not used after passing it to v4l2_fwnode_endpoint_parse() its
> refcount can be decremented immediately and at one location.
>
> Signed-off-by: Nicholas Mc Guire <[email protected]>
Acked-by: Hugues Fruchet <[email protected]>

> ---
>
> Issue found during code reading.
>
> Patch was compile tested with: x86_64_defconfig, MEDIA_SUPPORT=y
> MEDIA_CAMERA_SUPPORT=y, V4L_PLATFORM_DRIVERS=y, OF=y, COMPILE_TEST=y
> CONFIG_VIDEO_STM32_DCMI=y
> (There are a few sparse warnings - but unrelated to the lines changed)
>
> Patch is against 4.17.0 (localversion-next is next-20180608)
>
> drivers/media/platform/stm32/stm32-dcmi.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index 2e1933d..0b61042 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -1696,23 +1696,20 @@ static int dcmi_probe(struct platform_device *pdev)
> }
>
> ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(np), &ep);
> + of_node_put(np);
> if (ret) {
> dev_err(&pdev->dev, "Could not parse the endpoint\n");
> - of_node_put(np);
> return -ENODEV;
> }
>
> if (ep.bus_type == V4L2_MBUS_CSI2) {
> dev_err(&pdev->dev, "CSI bus not supported\n");
> - of_node_put(np);
> return -ENODEV;
> }
> dcmi->bus.flags = ep.bus.parallel.flags;
> dcmi->bus.bus_width = ep.bus.parallel.bus_width;
> dcmi->bus.data_shift = ep.bus.parallel.data_shift;
>
> - of_node_put(np);
> -
> irq = platform_get_irq(pdev, 0);
> if (irq <= 0) {
> dev_err(&pdev->dev, "Could not get irq\n");
>