@@ -208,15 +208,19 @@ uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
struct v4l2_event v4l2_event;
struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
- if (uvc->event_setup_out) {
- uvc->event_setup_out = 0;
+ if (uvc->event_status) {
+ uvc->event_status = 0;
+ return;
+ }
+ if (uvc->event_setup_out) {
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_DATA;
uvc_event->data.length = req->actual;
memcpy(&uvc_event->data.data, req->buf, req->actual);
memcpy(&uvc_event->data.setup, &uvc->control_setup,
sizeof(uvc_event->data.setup));
+
v4l2_event_queue(&uvc->vdev, &v4l2_event);
}
}
@@ -242,6 +246,8 @@ uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
uvc->event_length = le16_to_cpu(ctrl->wLength);
memcpy(&uvc->control_setup, ctrl, sizeof(uvc->control_setup));
+ uvc->event_status = 0;
+
if (uvc->event_setup_out) {
struct usb_request *req = uvc->control_req;
@@ -251,6 +257,7 @@ uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
*/
req->length = uvc->event_length;
req->zero = 0;
+ req->explicit_status = 1;
usb_ep_queue(f->config->cdev->gadget->ep0, req, GFP_KERNEL);
} else {
struct v4l2_event v4l2_event;
@@ -171,6 +171,7 @@ struct uvc_device {
/* Events */
unsigned int event_length;
unsigned int event_setup_out : 1;
+ unsigned int event_status : 1;
};
static inline struct uvc_device *to_uvc(struct usb_function *f)
@@ -35,15 +35,27 @@ uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
struct usb_composite_dev *cdev = uvc->func.config->cdev;
struct usb_request *req = uvc->control_req;
+ if (data->length < 0)
+ return usb_ep_set_halt(cdev->gadget->ep0);
+
/*
* For control OUT transfers the request has been enqueued synchronously
- * by the setup handler, there's nothing to be done here.
+ * by the setup handler, we just need to tell the UDC whether to ACK or
+ * STALL the control transfer.
*/
- if (uvc->event_setup_out)
- return 0;
-
- if (data->length < 0)
- return usb_ep_set_halt(cdev->gadget->ep0);
+ if (uvc->event_setup_out) {
+ /*
+ * The length field carries the control request status.
+ * Negative values signal a STALL and zero values an ACK.
+ * Positive values are not valid as there is no data to send
+ * back in the status stage.
+ */
+ if (data->length > 0)
+ return -EINVAL;
+
+ uvc->event_status = 1;
+ return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
+ }
req->length = min_t(unsigned int, uvc->event_length, data->length);
req->zero = data->length < uvc->event_length;
We now have a mechanism to signal the UDC driver to reply to a control OUT request with STALL or ACK, and we have packaged the setup stage data and the data stage data of a control OUT request into a single UVC_EVENT_DATA for userspace to consume. After telling the UDC to delay the status stage, the ioctl UVCIOC_SEND_RESPONSE should be called to notify the UDC driver to reply with STALL or ACK, for control OUT requests. In the case of a control IN request, the ioctl sends the UVC data as before. This means that the completion handler will also be called for the status stage, so make the UVC gadget driver aware of if the completion handler is called for the status stage, and do nothing (as opposed to giving userspace the UVC data again). Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> --- No change from v6 Changes from v5: - add event_status flag and use to keep track of whether or not the gadget is in the status stage or not - do nothing if the completion handler is called during the status stage No change from v4 No change from v3 Changes from v2: - calling usb_ep_set_halt in uvc_send_response if data->length < 0 is now common for both IN and OUT transfers so make that check common - remove now unnecessary field setting for the usb_request to be queued for the status stage Changes from v1: - remove usb_ep_delay_status call from the old proposed API - changed portions of uvc_send_response to match v2 API - remove UDC warning that send_response is not implemented drivers/usb/gadget/function/f_uvc.c | 11 +++++++++-- drivers/usb/gadget/function/uvc.h | 1 + drivers/usb/gadget/function/uvc_v4l2.c | 24 ++++++++++++++++++------ 3 files changed, 28 insertions(+), 8 deletions(-)