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>
Reviewed-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Link: https://lore.kernel.org/r/20230919103939.1367659-1-u.kleine-koenig@pengutronix.deSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919103939.1367659-1-u.kleine-koenig@pengutronix.de

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,

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,

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__ */