Mailing List Archive: [PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with _

[PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with __free

Apr 27, 2024, 2:56 AM

Post #1 of 4 (20 views)

Use the new cleanup magic to replace of_node_put() with
__free(device_node) marking to auto release and to simplify the error
paths.

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: R Sundar <prosunofficial@gmail.com>
---
drivers/media/i2c/st-mipid02.c | 37 +++++++++-------------------------
1 file changed, 9 insertions(+), 28 deletions(-)

diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
index f250640729ca..d42a306530f3 100644
--- a/drivers/media/i2c/st-mipid02.c
+++ b/drivers/media/i2c/st-mipid02.c
@@ -715,31 +715,28 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
struct i2c_client *client = bridge->i2c_client;
struct v4l2_async_connection *asd;
- struct device_node *ep_node;
int ret;

/* parse rx (endpoint 0) */
- ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
- 0, 0);
+ struct device_node *ep_node __free(device_node) =
+ of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 0, 0);
if (!ep_node) {
dev_err(&client->dev, "unable to find port0 ep");
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}

ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
if (ret) {
dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
ret);
- goto error_of_node_put;
+ return ret;
}

/* do some sanity checks */
if (ep.bus.mipi_csi2.num_data_lanes > 2) {
dev_err(&client->dev, "max supported data lanes is 2 / got %d",
ep.bus.mipi_csi2.num_data_lanes);
- ret = -EINVAL;
- goto error_of_node_put;
+ return -EINVAL;
}

/* register it for later use */
@@ -750,7 +747,6 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
of_fwnode_handle(ep_node),
struct v4l2_async_connection);
- of_node_put(ep_node);

if (IS_ERR(asd)) {
dev_err(&client->dev, "fail to register asd to notifier %ld",
@@ -764,46 +760,31 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
v4l2_async_nf_cleanup(&bridge->notifier);

return ret;
-
-error_of_node_put:
- of_node_put(ep_node);
-error:
-
- return ret;
}

static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
{
struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
struct i2c_client *client = bridge->i2c_client;
- struct device_node *ep_node;
int ret;

/* parse tx (endpoint 2) */
- ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
- 2, 0);
+ struct device_node *ep_node =
+ of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 2, 0);
if (!ep_node) {
dev_err(&client->dev, "unable to find port1 ep");
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}

ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
if (ret) {
dev_err(&client->dev, "Could not parse v4l2 endpoint\n");
- goto error_of_node_put;
+ return ret;
}

- of_node_put(ep_node);
bridge->tx = ep;

return 0;
-
-error_of_node_put:
- of_node_put(ep_node);
-error:
-
- return -EINVAL;
}

static int mipid02_probe(struct i2c_client *client)
--
2.34.1

Re: [PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with __free [ In reply to ]

benjamin.mugnier at foss

Apr 29, 2024, 1:52 AM

Post #2 of 4 (16 views)

Permalink

Hi,

Thank you for your patch.

On 4/27/24 11:56, R Sundar wrote:
> Use the new cleanup magic to replace of_node_put() with
> __free(device_node) marking to auto release and to simplify the error
> paths.
>
> Suggested-by: Julia Lawall <julia.lawall@inria.fr>
> Signed-off-by: R Sundar <prosunofficial@gmail.com>

I was not aware of this kind of auto release mechanism. Thanks for
bringing that to my eyes.

Now I looked in /drivers/media and couldn't find such structure. All
drivers seem to follow the goto error_of_node_put style.
As I'm unsure if we want to introduce such magic, could either Laurent
or Sakari comment on this ?

> ---
> drivers/media/i2c/st-mipid02.c | 37 +++++++++-------------------------
> 1 file changed, 9 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
> index f250640729ca..d42a306530f3 100644
> --- a/drivers/media/i2c/st-mipid02.c
> +++ b/drivers/media/i2c/st-mipid02.c
> @@ -715,31 +715,28 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
> struct i2c_client *client = bridge->i2c_client;
> struct v4l2_async_connection *asd;
> - struct device_node *ep_node;
> int ret;
>
> /* parse rx (endpoint 0) */
> - ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
> - 0, 0);
> + struct device_node *ep_node __free(device_node) =
> + of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 0, 0);
> if (!ep_node) {
> dev_err(&client->dev, "unable to find port0 ep");
> - ret = -EINVAL;
> - goto error;
> + return -EINVAL;
> }
>
> ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
> if (ret) {
> dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
> ret);
> - goto error_of_node_put;
> + return ret;
> }
>
> /* do some sanity checks */
> if (ep.bus.mipi_csi2.num_data_lanes > 2) {
> dev_err(&client->dev, "max supported data lanes is 2 / got %d",
> ep.bus.mipi_csi2.num_data_lanes);
> - ret = -EINVAL;
> - goto error_of_node_put;
> + return -EINVAL;
> }
>
> /* register it for later use */
> @@ -750,7 +747,6 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
> of_fwnode_handle(ep_node),
> struct v4l2_async_connection);
> - of_node_put(ep_node);
>
> if (IS_ERR(asd)) {
> dev_err(&client->dev, "fail to register asd to notifier %ld",
> @@ -764,46 +760,31 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
> v4l2_async_nf_cleanup(&bridge->notifier);
>
> return ret;
> -
> -error_of_node_put:
> - of_node_put(ep_node);
> -error:
> -
> - return ret;
> }
>
> static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
> {
> struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
> struct i2c_client *client = bridge->i2c_client;
> - struct device_node *ep_node;
> int ret;
>
> /* parse tx (endpoint 2) */
> - ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
> - 2, 0);
> + struct device_node *ep_node =
> + of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 2, 0);

Shouldn't there be a '__free' here too ?

> if (!ep_node) {
> dev_err(&client->dev, "unable to find port1 ep");
> - ret = -EINVAL;
> - goto error;
> + return -EINVAL;
> }
>
> ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
> if (ret) {
> dev_err(&client->dev, "Could not parse v4l2 endpoint\n");
> - goto error_of_node_put;
> + return ret;
> }
>
> - of_node_put(ep_node);
> bridge->tx = ep;
>
> return 0;
> -
> -error_of_node_put:
> - of_node_put(ep_node);
> -error:
> -
> - return -EINVAL;
> }
>
> static int mipid02_probe(struct i2c_client *client)

--
Regards,

Benjamin

Re: [PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with __free [ In reply to ]

sakari.ailus at linux

Apr 29, 2024, 2:04 AM

Post #3 of 4 (16 views)

Permalink

Hi Benjamin,

On Mon, Apr 29, 2024 at 10:52:34AM +0200, Benjamin Mugnier wrote:
> Hi,
>
> Thank you for your patch.
>
> On 4/27/24 11:56, R Sundar wrote:
> > Use the new cleanup magic to replace of_node_put() with
> > __free(device_node) marking to auto release and to simplify the error
> > paths.
> >
> > Suggested-by: Julia Lawall <julia.lawall@inria.fr>
> > Signed-off-by: R Sundar <prosunofficial@gmail.com>
>
> I was not aware of this kind of auto release mechanism. Thanks for
> bringing that to my eyes.
>
> Now I looked in /drivers/media and couldn't find such structure. All
> drivers seem to follow the goto error_of_node_put style.
> As I'm unsure if we want to introduce such magic, could either Laurent
> or Sakari comment on this ?

It's new and little used so far. I don't have concerns using it, although
it's mostly useful in cases where all exit paths release the same resource.

--
Kind regards,

Sakari Ailus

Re: [PATCH linux-next] media: i2c: st-mipid02: replace of_node_put() with __free [ In reply to ]

prosunofficial at gmail

Apr 29, 2024, 9:02 AM

Post #4 of 4 (16 views)

Permalink

On 29/04/24 14:22, Benjamin Mugnier wrote:
> Hi,
>
> Thank you for your patch.
>
> On 4/27/24 11:56, R Sundar wrote:
>> Use the new cleanup magic to replace of_node_put() with
>> __free(device_node) marking to auto release and to simplify the error
>> paths.
>>
>> Suggested-by: Julia Lawall <julia.lawall@inria.fr>
>> Signed-off-by: R Sundar <prosunofficial@gmail.com>
>
> I was not aware of this kind of auto release mechanism. Thanks for
> bringing that to my eyes.
>
> Now I looked in /drivers/media and couldn't find such structure. All
> drivers seem to follow the goto error_of_node_put style.
> As I'm unsure if we want to introduce such magic, could either Laurent
> or Sakari comment on this ?
>
>> ---
>> drivers/media/i2c/st-mipid02.c | 37 +++++++++-------------------------
>> 1 file changed, 9 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
>> index f250640729ca..d42a306530f3 100644
>> --- a/drivers/media/i2c/st-mipid02.c
>> +++ b/drivers/media/i2c/st-mipid02.c
>> @@ -715,31 +715,28 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>> struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
>> struct i2c_client *client = bridge->i2c_client;
>> struct v4l2_async_connection *asd;
>> - struct device_node *ep_node;
>> int ret;
>>
>> /* parse rx (endpoint 0) */
>> - ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
>> - 0, 0);
>> + struct device_node *ep_node __free(device_node) =
>> + of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 0, 0);
>> if (!ep_node) {
>> dev_err(&client->dev, "unable to find port0 ep");
>> - ret = -EINVAL;
>> - goto error;
>> + return -EINVAL;
>> }
>>
>> ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
>> if (ret) {
>> dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
>> ret);
>> - goto error_of_node_put;
>> + return ret;
>> }
>>
>> /* do some sanity checks */
>> if (ep.bus.mipi_csi2.num_data_lanes > 2) {
>> dev_err(&client->dev, "max supported data lanes is 2 / got %d",
>> ep.bus.mipi_csi2.num_data_lanes);
>> - ret = -EINVAL;
>> - goto error_of_node_put;
>> + return -EINVAL;
>> }
>>
>> /* register it for later use */
>> @@ -750,7 +747,6 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>> asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
>> of_fwnode_handle(ep_node),
>> struct v4l2_async_connection);
>> - of_node_put(ep_node);
>>
>> if (IS_ERR(asd)) {
>> dev_err(&client->dev, "fail to register asd to notifier %ld",
>> @@ -764,46 +760,31 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>> v4l2_async_nf_cleanup(&bridge->notifier);
>>
>> return ret;
>> -
>> -error_of_node_put:
>> - of_node_put(ep_node);
>> -error:
>> -
>> - return ret;
>> }
>>
>> static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
>> {
>> struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
>> struct i2c_client *client = bridge->i2c_client;
>> - struct device_node *ep_node;
>> int ret;
>>
>> /* parse tx (endpoint 2) */
>> - ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
>> - 2, 0);
>> + struct device_node *ep_node =
>> + of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 2, 0);
>
> Shouldn't there be a '__free' here too ?
>

my Bad.
Yes, It should come here also. Thanks!!
Will update the patch.

Thanks,
Sundar