Hello,
On 2015-11-23 16:32, Alan Stern wrote:
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.
'pending' handle is added to gadget_driver_pending_list in
usb_gadget_probe_driver(),
then when udc is available it is removed from this list and bound to the
given driver.
In usb_gadget_unregister_driver() the gadget is either unbound from the
udc or if is
was not bound to any udc, removed from pending list. I see no need for
adding
INIT_LIST_HEAD.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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