[PATCH 4/5] usb: gadget: lpc32xx_udc: Convert to platform remove callback returning void

Uwe Kleine-König u.kleine-koenig at pengutronix.de
Mon Nov 20 13:58:35 PST 2023


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() will be renamed to .remove().

In the error path emit an error message replacing the (less useful)
message by the core. Apart from the improved error message there is no
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 drivers/usb/gadget/udc/lpc32xx_udc.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
index a917cc9a32ab..d5f29f8fe481 100644
--- a/drivers/usb/gadget/udc/lpc32xx_udc.c
+++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
@@ -3174,13 +3174,16 @@ static int lpc32xx_udc_probe(struct platform_device *pdev)
 	return retval;
 }
 
-static int lpc32xx_udc_remove(struct platform_device *pdev)
+static void lpc32xx_udc_remove(struct platform_device *pdev)
 {
 	struct lpc32xx_udc *udc = platform_get_drvdata(pdev);
 
 	usb_del_gadget_udc(&udc->gadget);
-	if (udc->driver)
-		return -EBUSY;
+	if (udc->driver) {
+		dev_err(&pdev->dev,
+			"Driver still in use but removing anyhow\n");
+		return;
+	}
 
 	udc_clk_set(udc, 1);
 	udc_disable(udc);
@@ -3194,8 +3197,6 @@ static int lpc32xx_udc_remove(struct platform_device *pdev)
 			  udc->udca_v_base, udc->udca_p_base);
 
 	clk_disable_unprepare(udc->usb_slv_clk);
-
-	return 0;
 }
 
 #ifdef CONFIG_PM
@@ -3255,7 +3256,7 @@ MODULE_DEVICE_TABLE(of, lpc32xx_udc_of_match);
 
 static struct platform_driver lpc32xx_udc_driver = {
 	.probe		= lpc32xx_udc_probe,
-	.remove		= lpc32xx_udc_remove,
+	.remove_new	= lpc32xx_udc_remove,
 	.shutdown	= lpc32xx_udc_shutdown,
 	.suspend	= lpc32xx_udc_suspend,
 	.resume		= lpc32xx_udc_resume,
-- 
2.42.0




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