On 04/19/2011 05:23 PM, ext Michal Nazarewicz wrote:
On Tue, 19 Apr 2011 15:33:52 +0200, Roger Quadros <roger.quadros@xxxxxxxxx> wrote:
@@ -895,6 +904,14 @@ composite_setup(struct usb_gadget *gadget, const struct
usb_ctrlrequest *ctrl)
if (w_value && !f->set_alt)
break;
value = f->set_alt(f, w_index, w_value);
+ if (value == USB_GADGET_DELAYED_STATUS) {
+ DBG(cdev,
+ "%s: interface %d (%s) requested delayed status\n",
+ __func__, intf, f->name);
+ cdev->delayed_status++;
Do we need it to be a counter? Won't simple flag do?
Counter because multiple interfaces could return USB_GADGET_DELAYED_STATUS
and we need to know how many of them call usb_composite_setup_continue() before
we actually complete the control transfer.
+ DBG(cdev, "delayed_status count %d\n",
+ cdev->delayed_status);
+ }
break;
case USB_REQ_GET_INTERFACE:
if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
@@ -1289,3 +1310,41 @@ void usb_composite_unregister(struct
usb_composite_driver *driver)
return;
usb_gadget_unregister_driver(&composite_driver);
}
+
+/**
+ * usb_composite_setup_continue() - Continue the delayed setup transfer
+ * @cdev: the composite device who's setup transfer was delayed
+ *
+ * This function must be called by the USB function driver to continue
+ * with the setup transfer's data/status phase in case it had requested to
+ * delay the status phase. A USB function's setup handler (e.g. set_alt())
+ * can request the composite framework to delay the setup request's status phase
+ * by returning USB_GADGET_DELAYED_STATUS.
+ */
+void usb_composite_setup_continue(struct usb_composite_dev *cdev)
+{
+ int value;
+ struct usb_request *req = cdev->req;
+ unsigned long flags;
+
+ DBG(cdev, "%s\n", __func__);
+ spin_lock_irqsave(&cdev->lock, flags);
+
+ if (cdev->delayed_status == 0) {
+ WARN(cdev, "%s: Unexpected call\n", __func__);
+
+ } else if (--cdev->delayed_status == 0) {
+ DBG(cdev, "%s: Completing delayed status\n", __func__);
+ req->length = 0;
+ req->zero = 1;
+ value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0) {
+ DBG(cdev, "ep_queue --> %d\n", value);
+ req->status = 0;
+ composite_setup_complete(cdev->gadget->ep0, req);
+ }
+ }Data/status stage.
+
+ spin_unlock_irqrestore(&cdev->lock, flags);
+}
It's just my opinion but I dislike how it looks almost identical to the end
of composite_setup. I would rather make it more general (take value as
argument for instance) and let composite_setup() call it.
Yes that could be done. I'll try to do so in the next iteration.
diff --git a/include/linux/usb/composite.h @@ -37,6 +37,15 @@
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
+/*
+ * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
+ * wish to delay the status phase of the setup transfer till they are
+ * ready. The composite framework will then delay the data/status phase
+ * of the setup transfer till all the function drivers that requested for
+ * USB_GADGET_DELAYED_STAUS, invoke usb_composite_setup_continue().
+ *
+ */
+#define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */
I was wondering if we could change it to something like EDELAYED and put it to
<include/linux/errno.h>. Just thinking, it may be a bad idea.
I would not do it.
Thanks for review.
--
regards,
-roger
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