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 Also, the patch removes a few superseded callbacks from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 <st...@rowland.harvard.edu>
---
[as1874]
drivers/usb/gadget/udc/core.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
Index: usb-4.x/drivers/usb/gadget/udc/core.c
===================================================================
--- usb-4.x.orig/drivers/usb/gadget/udc/core.c
+++ usb-4.x/drivers/usb/gadget/udc/core.c
@@ -672,6 +672,9 @@ 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)
@@ -693,8 +696,10 @@ int usb_gadget_disconnect(struct usb_gad
}
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);
@@ -1263,7 +1268,6 @@ static void usb_gadget_remove_driver(str
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);
@@ -1453,7 +1457,6 @@ static ssize_t soft_connect_store(struct
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);
