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Subject[PATCH 9/9] usb: musb: musb_am335x: reinstate module loading/unloading support
Date
There is no need to throw the baby out with the bath due to a bad
failure analysis. The commit:
7adb5c876e9c usb: musb: Fix panic upon musb_am335x module removal
came to a wrong conclusion about the cause of the crash it was
"fixing". The real culprit was the phy-am335x module that was removed
from underneath its users that were still referencing data from it.
After having fixed this in a previous patch, module unloading can be
reinstated.

Another bug with module loading/unloading was the fact, that after
removing the devices instantiated from DT their 'OF_POPULATED' flag
was still set, so that re-loading the module after an unload had no
effect. This is also fixed in this patch.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
---
drivers/usb/musb/musb_am335x.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/musb/musb_am335x.c b/drivers/usb/musb/musb_am335x.c
index 164c868..152a6f5 100644
--- a/drivers/usb/musb/musb_am335x.c
+++ b/drivers/usb/musb/musb_am335x.c
@@ -19,6 +19,22 @@ err:
return ret;
}

+static int of_remove_populated_child(struct device *dev, void *d)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ of_device_unregister(pdev);
+ of_node_clear_flag(pdev->dev.of_node, OF_POPULATED);
+ return 0;
+}
+
+static int am335x_child_remove(struct platform_device *pdev)
+{
+ device_for_each_child(&pdev->dev, NULL, of_remove_populated_child);
+ pm_runtime_disable(&pdev->dev);
+ return 0;
+}
+
static const struct of_device_id am335x_child_of_match[] = {
{ .compatible = "ti,am33xx-usb" },
{ }
@@ -27,17 +43,14 @@ MODULE_DEVICE_TABLE(of, am335x_child_of_match);

static struct platform_driver am335x_child_driver = {
.probe = am335x_child_probe,
+ .remove = am335x_child_remove,
.driver = {
.name = "am335x-usb-childs",
.of_match_table = am335x_child_of_match,
},
};

-static int __init am335x_child_init(void)
-{
- return platform_driver_register(&am335x_child_driver);
-}
-module_init(am335x_child_init);
+module_platform_driver(am335x_child_driver);

MODULE_DESCRIPTION("AM33xx child devices");
MODULE_LICENSE("GPL v2");
--
1.7.10.4
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