diff mbox series

[01/14] power: reset: at91-poweroff: Stop using module_platform_driver_probe()

Message ID 20231104211501.3676352-17-u.kleine-koenig@pengutronix.de
State Accepted
Commit 099806de68b75a0fe114376b1ee162fdff572ecc
Headers show
Series power: reset: Drop platform_driver_probe() and convert to platform remove callback returning void | expand

Commit Message

Uwe Kleine-König Nov. 4, 2023, 9:15 p.m. UTC
On today's platforms the benefit of platform_driver_probe() isn't that
relevant any more. It allows to drop some code after booting (or module
loading) for .probe() and discard the .remove() function completely if
the driver is built-in. This typically saves a few 100k.

The downside of platform_driver_probe() is that the driver cannot be
bound and unbound at runtime which is ancient and so slightly
complicates testing. There are also thoughts to deprecate
platform_driver_probe() because it adds some complexity in the driver
core for little gain. Also many drivers don't use it correctly. This
driver for example misses to mark the driver struct with __ref which is
needed to suppress a (W=1) modpost warning.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/power/reset/at91-poweroff.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Claudiu Nov. 8, 2023, 6:54 a.m. UTC | #1
On 04.11.2023 23:15, Uwe Kleine-König wrote:
> On today's platforms the benefit of platform_driver_probe() isn't that
> relevant any more. It allows to drop some code after booting (or module
> loading) for .probe() and discard the .remove() function completely if
> the driver is built-in. This typically saves a few 100k.
> 
> The downside of platform_driver_probe() is that the driver cannot be
> bound and unbound at runtime which is ancient and so slightly
> complicates testing. There are also thoughts to deprecate
> platform_driver_probe() because it adds some complexity in the driver
> core for little gain. Also many drivers don't use it correctly. This
> driver for example misses to mark the driver struct with __ref which is
> needed to suppress a (W=1) modpost warning.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

> ---
>  drivers/power/reset/at91-poweroff.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
> index dd5399785b69..83567428ab43 100644
> --- a/drivers/power/reset/at91-poweroff.c
> +++ b/drivers/power/reset/at91-poweroff.c
> @@ -149,7 +149,7 @@ static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
>  	writel(wakeup_mode | mode, at91_shdwc.shdwc_base + AT91_SHDW_MR);
>  }
>  
> -static int __init at91_poweroff_probe(struct platform_device *pdev)
> +static int at91_poweroff_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np;
>  	u32 ddr_type;
> @@ -202,7 +202,7 @@ static int __init at91_poweroff_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int __exit at91_poweroff_remove(struct platform_device *pdev)
> +static int at91_poweroff_remove(struct platform_device *pdev)
>  {
>  	if (pm_power_off == at91_poweroff)
>  		pm_power_off = NULL;
> @@ -224,13 +224,14 @@ static const struct of_device_id at91_poweroff_of_match[] = {
>  MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
>  
>  static struct platform_driver at91_poweroff_driver = {
> -	.remove = __exit_p(at91_poweroff_remove),
> +	.probe = at91_poweroff_probe,
> +	.remove = at91_poweroff_remove,
>  	.driver = {
>  		.name = "at91-poweroff",
>  		.of_match_table = at91_poweroff_of_match,
>  	},
>  };
> -module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
> +module_platform_driver(at91_poweroff_driver);
>  
>  MODULE_AUTHOR("Atmel Corporation");
>  MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");
diff mbox series

Patch

diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index dd5399785b69..83567428ab43 100644
--- a/drivers/power/reset/at91-poweroff.c
+++ b/drivers/power/reset/at91-poweroff.c
@@ -149,7 +149,7 @@  static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
 	writel(wakeup_mode | mode, at91_shdwc.shdwc_base + AT91_SHDW_MR);
 }
 
-static int __init at91_poweroff_probe(struct platform_device *pdev)
+static int at91_poweroff_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
 	u32 ddr_type;
@@ -202,7 +202,7 @@  static int __init at91_poweroff_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int __exit at91_poweroff_remove(struct platform_device *pdev)
+static int at91_poweroff_remove(struct platform_device *pdev)
 {
 	if (pm_power_off == at91_poweroff)
 		pm_power_off = NULL;
@@ -224,13 +224,14 @@  static const struct of_device_id at91_poweroff_of_match[] = {
 MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
 
 static struct platform_driver at91_poweroff_driver = {
-	.remove = __exit_p(at91_poweroff_remove),
+	.probe = at91_poweroff_probe,
+	.remove = at91_poweroff_remove,
 	.driver = {
 		.name = "at91-poweroff",
 		.of_match_table = at91_poweroff_of_match,
 	},
 };
-module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
+module_platform_driver(at91_poweroff_driver);
 
 MODULE_AUTHOR("Atmel Corporation");
 MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");