usb: gadget: at91_udc: 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() 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@pengutronix.de>
Link: https://lore.kernel.org/r/20231120215830.71071-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/at91_udc.c b/drivers/usb/gadget/udc/at91_udc.c
index 30ea4a9d5301fca5864d37f485753babc06eb0ad..e3bf17a98b380650cef9b3c007d603fd8feba984 100644 (file)
--- a/drivers/usb/gadget/udc/at91_udc.c
+++ b/drivers/usb/gadget/udc/at91_udc.c
@@ -1924,7 +1924,7 @@ err_unprepare_fclk:
        return retval;
 }
 
-static int at91udc_remove(struct platform_device *pdev)
+static void at91udc_remove(struct platform_device *pdev)
 {
        struct at91_udc *udc = platform_get_drvdata(pdev);
        unsigned long   flags;
@@ -1932,8 +1932,11 @@ static int at91udc_remove(struct platform_device *pdev)
        DBG("remove\n");
 
        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;
+       }
 
        spin_lock_irqsave(&udc->lock, flags);
        pullup(udc, 0);
@@ -1943,8 +1946,6 @@ static int at91udc_remove(struct platform_device *pdev)
        remove_debug_file(udc);
        clk_unprepare(udc->fclk);
        clk_unprepare(udc->iclk);
-
-       return 0;
 }
 
 #ifdef CONFIG_PM
@@ -2001,7 +2002,7 @@ static int at91udc_resume(struct platform_device *pdev)
 
 static struct platform_driver at91_udc_driver = {
        .probe          = at91udc_probe,
-       .remove         = at91udc_remove,
+       .remove_new     = at91udc_remove,
        .shutdown       = at91udc_shutdown,
        .suspend        = at91udc_suspend,
        .resume         = at91udc_resume,