driver core: platform: Emit a warning if a remove callback returned non-zero

The driver core ignores the return value of a bus' remove callback. However
a driver returning an error code is a hint that there is a problem,
probably a driver author who expects that returning e.g. -EBUSY has any
effect.

The right thing to do would be to make struct platform_driver::remove()
return void. With the immense number of platform drivers this is however a
big quest and I hope to prevent at least a few new drivers that return an
error code here.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210207211537.19992-1-uwe@kleine-koenig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 8456d83..e8e0a9c 100644 (file)
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1463,13 +1463,16 @@ static int platform_remove(struct device *_dev)
 {
        struct platform_driver *drv = to_platform_driver(_dev->driver);
        struct platform_device *dev = to_platform_device(_dev);
-       int ret = 0;
 
-       if (drv->remove)
-               ret = drv->remove(dev);
+       if (drv->remove) {
+               int ret = drv->remove(dev);
+
+               if (ret)
+                       dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n");
+       }
        dev_pm_domain_detach(_dev, true);
 
-       return ret;
+       return 0;
 }
 
 static void platform_shutdown(struct device *_dev)