On Fri, Jul 18, 2014 at 11:31:30AM +0200, Lothar Waßmann wrote:
> 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.
now this is a good commit log. I still can't see the need for the other
patch adding try_module_get(), though. Another thing, this needs to be
reviewed by DT folks too.
> Signed-off-by: Lothar Waßmann <LW@xxxxxxxxxxxxxxxxxxx>
> ---
> 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);
I don't think this should be called by drivers; rather by the bus.
> + 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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--
balbi
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