LinuxLists.cc - [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

2024-03-08 08:52:10

Subject: [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <[email protected]>
---
drivers/pps/clients/pps-gpio.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index 2f4b11b4dfcd..791fdc9326dd 100644
--- a/drivers/pps/clients/pps-gpio.c
+++ b/drivers/pps/clients/pps-gpio.c
@@ -220,7 +220,7 @@ static int pps_gpio_probe(struct platform_device *pdev)
return 0;
}

-static int pps_gpio_remove(struct platform_device *pdev)
+static void pps_gpio_remove(struct platform_device *pdev)
{
struct pps_gpio_device_data *data = platform_get_drvdata(pdev);

@@ -229,7 +229,6 @@ static int pps_gpio_remove(struct platform_device *pdev)
/* reset echo pin in any case */
gpiod_set_value(data->echo_pin, 0);
dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
- return 0;
}

static const struct of_device_id pps_gpio_dt_ids[] = {
@@ -240,7 +239,7 @@ MODULE_DEVICE_TABLE(of, pps_gpio_dt_ids);

static struct platform_driver pps_gpio_driver = {
.probe = pps_gpio_probe,
- .remove = pps_gpio_remove,
+ .remove_new = pps_gpio_remove,
.driver = {
.name = PPS_GPIO_NAME,
.of_match_table = pps_gpio_dt_ids,

base-commit: 8ffc8b1bbd505e27e2c8439d326b6059c906c9dd
--
2.43.0

2024-03-08 09:09:05

by Rodolfo Giometti

[permalink] [raw]

Subject: Re: [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

On 08/03/24 09:51, Uwe Kleine-König wrote:
> The .remove() callback for a platform driver returns an int which makes
> many driver authors wrongly assume it's possible to do error handling by
> returning an error code. However the value returned is ignored (apart
> from emitting a warning) and this typically results in resource leaks.
>
> To improve here there is a quest to make the remove callback return
> void. In the first step of this quest all drivers are converted to
> .remove_new(), which already returns void. Eventually after all drivers
> are converted, .remove_new() will be renamed to .remove().
>
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
>
> Signed-off-by: Uwe Kleine-König <[email protected]>

Acked-by: Rodolfo Giometti <[email protected]>

> ---
> drivers/pps/clients/pps-gpio.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
> index 2f4b11b4dfcd..791fdc9326dd 100644
> --- a/drivers/pps/clients/pps-gpio.c
> +++ b/drivers/pps/clients/pps-gpio.c
> @@ -220,7 +220,7 @@ static int pps_gpio_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int pps_gpio_remove(struct platform_device *pdev)
> +static void pps_gpio_remove(struct platform_device *pdev)
> {
> struct pps_gpio_device_data *data = platform_get_drvdata(pdev);
>
> @@ -229,7 +229,6 @@ static int pps_gpio_remove(struct platform_device *pdev)
> /* reset echo pin in any case */
> gpiod_set_value(data->echo_pin, 0);
> dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
> - return 0;
> }
>
> static const struct of_device_id pps_gpio_dt_ids[] = {
> @@ -240,7 +239,7 @@ MODULE_DEVICE_TABLE(of, pps_gpio_dt_ids);
>
> static struct platform_driver pps_gpio_driver = {
> .probe = pps_gpio_probe,
> - .remove = pps_gpio_remove,
> + .remove_new = pps_gpio_remove,
> .driver = {
> .name = PPS_GPIO_NAME,
> .of_match_table = pps_gpio_dt_ids,
>
> base-commit: 8ffc8b1bbd505e27e2c8439d326b6059c906c9dd

--
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Linux Device Driver [email protected]
Embedded Systems phone: +39 349 2432127
UNIX programming

2024-04-12 12:26:59

by Uwe Kleine-König

[permalink] [raw]

Subject: Re: [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

[Cc: += [email protected]]

On Fri, Mar 08, 2024 at 09:57:29AM +0100, Rodolfo Giometti wrote:
> On 08/03/24 09:51, Uwe Kleine-K?nig wrote:
> > The .remove() callback for a platform driver returns an int which makes
> > many driver authors wrongly assume it's possible to do error handling by
> > returning an error code. However the value returned is ignored (apart
> > from emitting a warning) and this typically results in resource leaks.
> >
> > To improve here there is a quest to make the remove callback return
> > void. In the first step of this quest all drivers are converted to
> > .remove_new(), which already returns void. Eventually after all drivers
> > are converted, .remove_new() will be renamed to .remove().
> >
> > Trivially convert this driver from always returning zero in the remove
> > callback to the void returning variant.
> >
> > Signed-off-by: Uwe Kleine-K?nig <[email protected]>
>
> Acked-by: Rodolfo Giometti <[email protected]>

The MAINTAINERS entry for drivers/pps lists you as single maintainer.
Who is expected to pick up this patch given that you "only" send an ack
but didn't pick up the patch? (Or only picked it up in a tree not
included in next.)

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |

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2024-04-12 13:01:04

by Rodolfo Giometti

[permalink] [raw]

Subject: Re: [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

2024-04-12 13:04:36

by Rodolfo Giometti

[permalink] [raw]

Subject: Re: [PATCH] pps: clients: gpio: Convert to platform remove callback returning void

On 12/04/24 14:26, Uwe Kleine-König wrote:
> [Cc: += [email protected]]
>
> On Fri, Mar 08, 2024 at 09:57:29AM +0100, Rodolfo Giometti wrote:
>> On 08/03/24 09:51, Uwe Kleine-König wrote:
>>> The .remove() callback for a platform driver returns an int which makes
>>> many driver authors wrongly assume it's possible to do error handling by
>>> returning an error code. However the value returned is ignored (apart
>>> from emitting a warning) and this typically results in resource leaks.
>>>
>>> To improve here there is a quest to make the remove callback return
>>> void. In the first step of this quest all drivers are converted to
>>> .remove_new(), which already returns void. Eventually after all drivers
>>> are converted, .remove_new() will be renamed to .remove().
>>>
>>> Trivially convert this driver from always returning zero in the remove
>>> callback to the void returning variant.
>>>
>>> Signed-off-by: Uwe Kleine-König <[email protected]>
>>
>> Acked-by: Rodolfo Giometti <[email protected]>
>
> The MAINTAINERS entry for drivers/pps lists you as single maintainer.
> Who is expected to pick up this patch given that you "only" send an ack
> but didn't pick up the patch? (Or only picked it up in a tree not
> included in next.)

Sorry. I forgot to add Greg Kroah-Hartman into CC. :-(

I've just resent the acked-by mail.

Ciao,

Rodolfo

--
GNU/Linux Solutions e-mail: [email protected]
Linux Device Driver [email protected]
Embedded Systems phone: +39 349 2432127
UNIX programming