drm: exynos: dsi: 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() is renamed to .remove().

samsung_dsim_remove() returned 0 unconditionally. Make it return void
instead to convert the two related platform drivers to use
.remove_new().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/gpu/drm/bridge/samsung-dsim.c   | 6 ++----
 drivers/gpu/drm/exynos/exynos_drm_dsi.c | 2 +-
 include/drm/bridge/samsung-dsim.h       | 2 +-
 3 files changed, 4 insertions(+), 6 deletions(-)


base-commit: 0663e1da5ba8e6459e3555ac12c62741668c0d30

2023년 9월 19일 (화) 오후 7:40, Uwe Kleine-König
<u.kleine-koenig@pengutronix.de>님이 작성:
>
> 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() is renamed to .remove().
>
> samsung_dsim_remove() returned 0 unconditionally. Make it return void
> instead to convert the two related platform drivers to use
> .remove_new().
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

It'd be better to go to drm-misc.

Reviewed-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>

Thanks,
Inki Dae

> ---
>  drivers/gpu/drm/bridge/samsung-dsim.c   | 6 ++----
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c | 2 +-
>  include/drm/bridge/samsung-dsim.h       | 2 +-
>  3 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index b1df91e37b1b..2b56a5bfe273 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1998,7 +1998,7 @@ int samsung_dsim_probe(struct platform_device *pdev)
>  }
>  EXPORT_SYMBOL_GPL(samsung_dsim_probe);
>
> -int samsung_dsim_remove(struct platform_device *pdev)
> +void samsung_dsim_remove(struct platform_device *pdev)
>  {
>         struct samsung_dsim *dsi = platform_get_drvdata(pdev);
>
> @@ -2006,8 +2006,6 @@ int samsung_dsim_remove(struct platform_device *pdev)
>
>         if (dsi->plat_data->host_ops && dsi->plat_data->host_ops->unregister_host)
>                 dsi->plat_data->host_ops->unregister_host(dsi);
> -
> -       return 0;
>  }
>  EXPORT_SYMBOL_GPL(samsung_dsim_remove);
>
> @@ -2107,7 +2105,7 @@ MODULE_DEVICE_TABLE(of, samsung_dsim_of_match);
>
>  static struct platform_driver samsung_dsim_driver = {
>         .probe = samsung_dsim_probe,
> -       .remove = samsung_dsim_remove,
> +       .remove_new = samsung_dsim_remove,
>         .driver = {
>                    .name = "samsung-dsim",
>                    .pm = &samsung_dsim_pm_ops,
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> index 69ea33cae651..2fe0e5f3f638 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> @@ -181,7 +181,7 @@ MODULE_DEVICE_TABLE(of, exynos_dsi_of_match);
>
>  struct platform_driver dsi_driver = {
>         .probe = samsung_dsim_probe,
> -       .remove = samsung_dsim_remove,
> +       .remove_new = samsung_dsim_remove,
>         .driver = {
>                    .name = "exynos-dsi",
>                    .owner = THIS_MODULE,
> diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
> index 6fc9bb2979e4..3f8050d523eb 100644
> --- a/include/drm/bridge/samsung-dsim.h
> +++ b/include/drm/bridge/samsung-dsim.h
> @@ -116,7 +116,7 @@ struct samsung_dsim {
>  };
>
>  extern int samsung_dsim_probe(struct platform_device *pdev);
> -extern int samsung_dsim_remove(struct platform_device *pdev);
> +extern void samsung_dsim_remove(struct platform_device *pdev);
>  extern const struct dev_pm_ops samsung_dsim_pm_ops;
>
>  #endif /* __SAMSUNG_DSIM__ */
>
> base-commit: 0663e1da5ba8e6459e3555ac12c62741668c0d30
> --
> 2.40.1
>

Hi,

On Tue, 19 Sep 2023 12:39:39 +0200, 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() is renamed to .remove().
> 
> [...]

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-next)

[1/1] drm: exynos: dsi: Convert to platform remove callback returning void
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=c1698c73f4aaef2fd406da1c0a92e1c8f7b7780c

Hi,

On Tue, 19 Sep 2023 12:39:39 +0200, 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() is renamed to .remove().
> 
> [...]

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-next)

[1/1] drm: exynos: dsi: Convert to platform remove callback returning void
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=c1698c73f4aaef2fd406da1c0a92e1c8f7b7780c