On Mon, 23 Nov 2015, Marek Szyprowski wrote:
> From: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
>
> Change behavior during registration of gadgets and
> gadget drivers in udc-core. Instead of previous
> approach when for successful probe of usb gadget driver
> at least one usb gadget should be already registered
> use another one where gadget drivers and gadgets
> can be registered in udc-core independently.
>
> Independent registration of gadgets and gadget drivers
> is useful for built-in into kernel gadget and gadget
> driver case - because it's possible that gadget is
> really probed only on late_init stage (due to deferred
> probe) whereas gadget driver's probe is silently failed
> on module_init stage due to no any UDC added.
>
> Also it is useful for modules case - now there is no
> difference what module to insert first: gadget module
> or gadget driver one.
>
> Tested-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
> [simplified code as requested by Alan Stern and Felipe Balbi,
> fixed checkpatch issues]
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Tested-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
I missed this the last time through...
> @@ -403,6 +408,18 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
> usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
> udc->vbus = true;
>
> + /* pick up one of pending gadget drivers */
> + list_for_each_entry(driver, &gadget_driver_pending_list, pending) {
> + if (!driver->udc_name || strcmp(driver->udc_name,
> + dev_name(&udc->dev)) == 0) {
> + ret = udc_bind_to_driver(udc, driver);
> + if (ret)
> + goto err4;
> + list_del(&driver->pending);
This has to be list_del_init(). And somewhere in
usb_gadget_probe_driver() you need to do
INIT_LIST_HEAD(&driver->pending).
> @@ -577,6 +596,10 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
> break;
> }
>
> + if (ret) {
> + list_del(&driver->pending);
Otherwise this will cause a crash or corrupt some random area of
memory.
Alan Stern
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