USB: add ep->enable

This patch (as944) adds an explicit "enabled" field to the
usb_host_endpoint structure and uses it in place of the current
mechanism.  This is merely a time-space tradeoff; it makes checking
whether URBs may be submitted to an endpoint simpler.  The existing
mechanism is efficient when converting urb->pipe to an endpoint
pointer, but it's not so efficient when urb->ep is used instead.

As a side effect, the procedure for enabling an endpoint is now a
little more complicated.  The ad-hoc inline code in usb.c and hub.c
for enabling ep0 is now replaced with calls to usb_enable_endpoint,
which is no longer static.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/hcd.c

@@ -943,7 +943,6 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 {
 	int			status;
 	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
-	struct usb_host_endpoint *ep;
 	unsigned long		flags;
 
 	if (!hcd)
@@ -960,9 +959,7 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
 	// FIXME:  verify that quiescing hc works right (RH cleans up)
 
 	spin_lock_irqsave(&hcd_urb_list_lock, flags);
-	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
-			[usb_pipeendpoint(urb->pipe)];
-	if (unlikely(ep != urb->ep))
+	if (unlikely(!urb->ep->enabled))
 		status = -ENOENT;
 	else if (unlikely (urb->reject))
 		status = -EPERM;

drivers/usb/core/hub.c

@@ -1999,7 +1999,7 @@ static void ep0_reinit(struct usb_device *udev)
 {
 	usb_disable_endpoint(udev, 0 + USB_DIR_IN);
 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
-	udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
+	usb_enable_endpoint(udev, &udev->ep0);
 }
 
 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)

drivers/usb/core/message.c

@@ -1013,8 +1013,10 @@ void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr)
 		ep = dev->ep_in[epnum];
 		dev->ep_in[epnum] = NULL;
 	}
-	if (ep && dev->bus)
+	if (ep) {
+		ep->enabled = 0;
 		usb_hcd_endpoint_disable(dev, ep);
+	}
 }
 
 /**
@@ -1096,23 +1098,21 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
  * Resets the endpoint toggle, and sets dev->ep_{in,out} pointers.
  * For control endpoints, both the input and output sides are handled.
  */
-static void
-usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep)
+void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep)
 {
-	unsigned int epaddr = ep->desc.bEndpointAddress;
-	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
-	int is_control;
+	int epnum = usb_endpoint_num(&ep->desc);
+	int is_out = usb_endpoint_dir_out(&ep->desc);
+	int is_control = usb_endpoint_xfer_control(&ep->desc);
 
-	is_control = ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
-			== USB_ENDPOINT_XFER_CONTROL);
-	if (usb_endpoint_out(epaddr) || is_control) {
+	if (is_out || is_control) {
 		usb_settoggle(dev, epnum, 1, 0);
 		dev->ep_out[epnum] = ep;
 	}
-	if (!usb_endpoint_out(epaddr) || is_control) {
+	if (!is_out || is_control) {
 		usb_settoggle(dev, epnum, 0, 0);
 		dev->ep_in[epnum] = ep;
 	}
+	ep->enabled = 1;
 }
 
 /*

drivers/usb/core/usb.c

@@ -260,7 +260,7 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
 	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
 	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
 	/* ep0 maxpacket comes later, from device descriptor */
-	dev->ep_in[0] = dev->ep_out[0] = &dev->ep0;
+	usb_enable_endpoint(dev, &dev->ep0);
 
 	/* Save readable and stable topology id, distinguishing devices
 	 * by location for diagnostics, tools, driver model, etc.  The

drivers/usb/core/usb.h

@@ -8,6 +8,8 @@ extern int usb_create_ep_files(struct device *parent, struct usb_host_endpoint *
 				struct usb_device *udev);
 extern void usb_remove_ep_files(struct usb_host_endpoint *endpoint);
 
+extern void usb_enable_endpoint(struct usb_device *dev,
+		struct usb_host_endpoint *ep);
 extern void usb_disable_endpoint (struct usb_device *dev, unsigned int epaddr);
 extern void usb_disable_interface (struct usb_device *dev,
 		struct usb_interface *intf);

include/linux/usb.h

@@ -52,6 +52,7 @@ struct ep_device;
  * @ep_dev: ep_device for sysfs info
  * @extra: descriptors following this endpoint in the configuration
  * @extralen: how many bytes of "extra" are valid
+ * @enabled: URBs may be submitted to this endpoint
  *
  * USB requests are always queued to a given endpoint, identified by a
  * descriptor within an active interface in a given USB configuration.
@@ -64,6 +65,7 @@ struct usb_host_endpoint {
 
 	unsigned char *extra;   /* Extra descriptors */
 	int extralen;
+	int enabled;
 };
 
 /* host-side wrapper for one interface setting's parsed descriptors */