[PATCH 00/10] usb: musb: Convert to platform remove callback returning void

[PATCH 00/10] usb: musb: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this patch series adapts the platform drivers below drivers/usb/musb
to use the .remove_new() callback. Compared to the traditional .remove()
callback .remove_new() returns no value. This is a good thing because
the driver core doesn't (and cannot) cope for errors during remove. The
only effect of a non-zero return value in .remove() is that the driver
core emits a warning. The device is removed anyhow and an early return
from .remove() usually yields a resource leak.

By changing the remove callback to return void driver authors cannot
reasonably assume any more that there is some kind of cleanup later.

All drivers touched here returned zero unconditionally in their remove
callback, so they could all be converted trivially to .remove_new().

Best regards
Uwe

Uwe Kleine-König (10):
  usb: musb: da8xx: Convert to platform remove callback returning void
  usb: musb: jz4740: Convert to platform remove callback returning void
  usb: musb: mediatek: Convert to platform remove callback returning void
  usb: musb: mpfs: Convert to platform remove callback returning void
  usb: musb: musb_core: Convert to platform remove callback returning void
  usb: musb: musb_dsps: Convert to platform remove callback returning void
  usb: musb: omap2430: Convert to platform remove callback returning void
  usb: musb: sunxi: Convert to platform remove callback returning void
  usb: musb: tusb6010: Convert to platform remove callback returning void
  usb: musb: ux500: Convert to platform remove callback returning void

 drivers/usb/musb/da8xx.c     | 6 ++----
 drivers/usb/musb/jz4740.c    | 6 ++----
 drivers/usb/musb/mediatek.c  | 6 ++----
 drivers/usb/musb/mpfs.c      | 6 ++----
 drivers/usb/musb/musb_core.c | 5 ++---
 drivers/usb/musb/musb_dsps.c | 6 ++----
 drivers/usb/musb/omap2430.c  | 6 ++----
 drivers/usb/musb/sunxi.c     | 6 ++----
 drivers/usb/musb/tusb6010.c  | 6 ++----
 drivers/usb/musb/ux500.c     | 6 ++----
 10 files changed, 20 insertions(+), 39 deletions(-)

base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
-- 
2.39.2

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[PATCH 03/10] usb: musb: mediatek: Convert to platform remove callback returning void

[Uwe Kleine-König]

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 (mostly) ignored
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.

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

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/usb/musb/mediatek.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/musb/mediatek.c b/drivers/usb/musb/mediatek.c
index 27b9bd258340..598ee5c0bf34 100644
--- a/drivers/usb/musb/mediatek.c
+++ b/drivers/usb/musb/mediatek.c
@@ -508,15 +508,13 @@ static int mtk_musb_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int mtk_musb_remove(struct platform_device *pdev)
+static void mtk_musb_remove(struct platform_device *pdev)
 {
 	struct mtk_glue *glue = platform_get_drvdata(pdev);
 	struct platform_device *usb_phy = glue->usb_phy;
 
 	platform_device_unregister(glue->musb_pdev);
 	usb_phy_generic_unregister(usb_phy);
-
-	return 0;
 }
 
 #ifdef CONFIG_OF
@@ -529,7 +527,7 @@ MODULE_DEVICE_TABLE(of, mtk_musb_match);
 
 static struct platform_driver mtk_musb_driver = {
 	.probe = mtk_musb_probe,
-	.remove = mtk_musb_remove,
+	.remove_new = mtk_musb_remove,
 	.driver = {
 		   .name = "musb-mtk",
 		   .of_match_table = of_match_ptr(mtk_musb_match),
-- 
2.39.2


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[PATCH 08/10] usb: musb: sunxi: Convert to platform remove callback returning void

[Uwe Kleine-König]

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 (mostly) ignored
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.

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

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/usb/musb/sunxi.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/musb/sunxi.c b/drivers/usb/musb/sunxi.c
index 9b622cd9b2bd..c5c6c4e09300 100644
--- a/drivers/usb/musb/sunxi.c
+++ b/drivers/usb/musb/sunxi.c
@@ -805,15 +805,13 @@ static int sunxi_musb_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int sunxi_musb_remove(struct platform_device *pdev)
+static void sunxi_musb_remove(struct platform_device *pdev)
 {
 	struct sunxi_glue *glue = platform_get_drvdata(pdev);
 	struct platform_device *usb_phy = glue->usb_phy;
 
 	platform_device_unregister(glue->musb_pdev);
 	usb_phy_generic_unregister(usb_phy);
-
-	return 0;
 }
 
 static const struct sunxi_musb_cfg sun4i_a10_musb_cfg = {
@@ -862,7 +860,7 @@ MODULE_DEVICE_TABLE(of, sunxi_musb_match);
 
 static struct platform_driver sunxi_musb_driver = {
 	.probe = sunxi_musb_probe,
-	.remove = sunxi_musb_remove,
+	.remove_new = sunxi_musb_remove,
 	.driver = {
 		.name = "musb-sunxi",
 		.of_match_table = sunxi_musb_match,
-- 
2.39.2


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Re: [PATCH 08/10] usb: musb: sunxi: Convert to platform remove callback returning void

[Jernej Škrabec]

Dne sreda, 05. april 2023 ob 16:10:07 CEST je Uwe Kleine-König napisal(a):
> 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 (mostly) ignored
> 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.
> 
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej



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