[PATCH 02/22] fb: atmel_lcdfb: Stop using platform_driver_probe()

Uwe Kleine-König u.kleine-koenig at pengutronix.de
Tue Nov 7 12:01:34 PST 2023


On Tue, Nov 07, 2023 at 10:17:43AM +0100, 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 also 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 __refdata which
> is needed to suppress a (W=1) modpost warning:
> 
> 	WARNING: modpost: drivers/video/fbdev/atmel_lcdfb: section mismatch in reference: atmel_lcdfb_driver+0x4 (section: .data) -> atmel_lcdfb_remove (section: .exit.text)
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> ---
>  drivers/video/fbdev/atmel_lcdfb.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/video/fbdev/atmel_lcdfb.c b/drivers/video/fbdev/atmel_lcdfb.c
> index a908db233409..b218731ef732 100644
> --- a/drivers/video/fbdev/atmel_lcdfb.c
> +++ b/drivers/video/fbdev/atmel_lcdfb.c
> @@ -1017,7 +1017,7 @@ static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
>  	return ret;
>  }
>  
> -static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> +static int atmel_lcdfb_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct fb_info *info;
> @@ -1223,7 +1223,7 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int __exit atmel_lcdfb_remove(struct platform_device *pdev)
> +static int atmel_lcdfb_remove(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct fb_info *info = dev_get_drvdata(dev);
> @@ -1301,7 +1301,8 @@ static int atmel_lcdfb_resume(struct platform_device *pdev)
>  #endif
>  
>  static struct platform_driver atmel_lcdfb_driver = {
> -	.remove		= __exit_p(atmel_lcdfb_remove),
> +	.probe		= atmel_lcdfb_probe,
> +	.remove		= atmel_lcdfb_remove,
>  	.suspend	= atmel_lcdfb_suspend,
>  	.resume		= atmel_lcdfb_resume,
>  	.driver		= {
> @@ -1310,7 +1311,7 @@ static struct platform_driver atmel_lcdfb_driver = {
>  	},
>  };
>  
> -module_platform_driver_probe(atmel_lcdfb_driver, atmel_lcdfb_probe);
> +module_platform_driver(atmel_lcdfb_driver, );

Argh, the , must be removed. I had this in my working copy but forgot to
squash it into this commit. Sorry!

Can you squash in the following please?:

diff --git a/drivers/video/fbdev/atmel_lcdfb.c b/drivers/video/fbdev/atmel_lcdfb.c
index 0531d6f6dcc5..88c75ae7d315 100644
--- a/drivers/video/fbdev/atmel_lcdfb.c
+++ b/drivers/video/fbdev/atmel_lcdfb.c
@@ -1308,8 +1308,7 @@ static struct platform_driver atmel_lcdfb_driver = {
 		.of_match_table	= atmel_lcdfb_dt_ids,
 	},
 };
-
-module_platform_driver(atmel_lcdfb_driver, );
+module_platform_driver(atmel_lcdfb_driver);
 
 MODULE_DESCRIPTION("AT91 LCD Controller framebuffer driver");
 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre at atmel.com>");

Best regards
Uwe

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