USB: gadget core: Issue ->disconnect() callback from usb_gadget_disconnect()

The gadget documentation doesn't state clearly whether a gadget
driver's ->disconnect() callback should be invoked when the D+ pullup
is turned off.  Some UDC drivers do this and some don't.  This patch
settles the issue by making the core function usb_gadget_disconnect()
issue the callback, so that UDC drivers don't need to worry about it.

A description of the new behavior is added to the function's
kerneldoc.  Also, the patch removes a few superseded callbacks from
other core routines.

Future patches will remove the ->disconnect() calls from the UDC
drivers that make them, as they are now unnecessary.  Until all those
patches are merged gadget drivers may receive extra ->disconnect()
callbacks, but this should be harmless.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Alan Stern 2018-08-10 15:32:25 -04:00 committed by Felipe Balbi
parent 6af19fd105
commit 0a55187a1e

View file

@ -690,6 +690,9 @@ EXPORT_SYMBOL_GPL(usb_gadget_connect);
* as a disconnect (when a VBUS session is active). Not all systems
* support software pullup controls.
*
* Following a successful disconnect, invoke the ->disconnect() callback
* for the current gadget driver so that UDC drivers don't need to.
*
* Returns zero on success, else negative errno.
*/
int usb_gadget_disconnect(struct usb_gadget *gadget)
@ -711,8 +714,10 @@ int usb_gadget_disconnect(struct usb_gadget *gadget)
}
ret = gadget->ops->pullup(gadget, 0);
if (!ret)
if (!ret) {
gadget->connected = 0;
gadget->udc->driver->disconnect(gadget);
}
out:
trace_usb_gadget_disconnect(gadget, ret);
@ -1281,7 +1286,6 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
usb_gadget_disconnect(udc->gadget);
udc->driver->disconnect(udc->gadget);
udc->driver->unbind(udc->gadget);
usb_gadget_udc_stop(udc);
@ -1471,7 +1475,6 @@ static ssize_t soft_connect_store(struct device *dev,
usb_gadget_connect(udc->gadget);
} else if (sysfs_streq(buf, "disconnect")) {
usb_gadget_disconnect(udc->gadget);
udc->driver->disconnect(udc->gadget);
usb_gadget_udc_stop(udc);
} else {
dev_err(dev, "unsupported command '%s'\n", buf);