On 10/12/18 7:42 AM, Peter Chen wrote:

quoted

quoted

+static struct usb_ep *cdns3_gadget_match_ep(struct usb_gadget *gadget,
+                                         struct usb_endpoint_descriptor *desc,
+                                         struct usb_ss_ep_comp_descriptor *comp_desc)
+{
+     struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
+     struct cdns3_endpoint *priv_ep;
+     unsigned long flags;
+
+     priv_ep = cdns3_find_available_ss_ep(priv_dev, desc);
+     if (IS_ERR(priv_ep)) {
+             dev_err(&priv_dev->dev, "no available ep\n");
+             return NULL;
+     }
+
+     dev_dbg(&priv_dev->dev, "match endpoint: %s\n", priv_ep->name);
+
+     spin_lock_irqsave(&priv_dev->lock, flags);
+     priv_ep->endpoint.desc = desc;
+     priv_ep->dir  = usb_endpoint_dir_in(desc) ? USB_DIR_IN : USB_DIR_OUT;
+     priv_ep->type = usb_endpoint_type(desc);
+
+     list_add_tail(&priv_ep->ep_match_pending_list,
+                   &priv_dev->ep_match_list);
+     spin_unlock_irqrestore(&priv_dev->lock, flags);
+     return &priv_ep->endpoint;
+}

Why do you need a custom match_ep?
doesn't usb_ep_autoconfig suffice?

You can check if EP is claimed or not by checking the ep->claimed flag.

It is a special requirement for this IP, the EP type and MaxPacketSize
changing can't be done at runtime, eg, at ep->enable. See below commit
for detail.

    usb: cdns3: gadget: configure all endpoints before set configuration

    Cadence IP has one limitation that all endpoints must be configured
    (Type & MaxPacketSize) before setting configuration through hardware
    register, it means we can't change endpoints configuration after
    set_configuration.

    In this patch, we add non-control endpoint through usb_ss->ep_match_list,
    which is added when the gadget driver uses usb_ep_autoconfig to configure
    specific endpoint; When the udc driver receives set_configurion request,
    it goes through usb_ss->ep_match_list, and configure all endpoints
    accordingly.

    At usb_ep_ops.enable/disable, we only enable and disable endpoint through
    ep_cfg register which can be changed after set_configuration, and do
    some software operation accordingly.

All this should be part of comments in code along with information about
controller versions which suffer from the errata.

Is there a version of controller available which does not have the
defect? Is there a future plan to fix this?

If any of that is yes, you probably want to handle this with runtime
detection of version (like done with DWC3_REVISION_XXX macros).
Sometimes the hardware-read versions themselves are incorrect, so its
better to introduce a version specific compatible too like
"cdns,usb-1.0.0" (as hinted to by Rob Herring as well).

Thanks,
Sekhar