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