USB: add reset endpoint operations

Wireless USB endpoint state has a sequence number and a current
window and not just a single toggle bit.  So allow HCDs to provide a
endpoint_reset method and call this or clear the software toggles as
required (after a clear halt, set configuration etc.).

usb_settoggle() and friends are then HCD internal and are moved into
core/hcd.h and all device drivers call usb_reset_endpoint() instead.

If the device endpoint state has been reset (with a clear halt) but
the host endpoint state has not then subsequent data transfers will
not complete. The device will only work again after it is reset or
disconnected.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed, 80 insertions, 26 deletions

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index df3c539f652..308609039c7 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -841,7 +841,7 @@ static int proc_resetep(struct dev_state *ps, void __user *arg)
 	ret = checkintf(ps, ret);
 	if (ret)
 		return ret;
-	usb_settoggle(ps->dev, ep & 0xf, !(ep & USB_DIR_IN), 0);
+	usb_reset_endpoint(ps->dev, ep);
 	return 0;
 }
 
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 81fa8506825..42b93da1085 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1539,6 +1539,32 @@ void usb_hcd_disable_endpoint(struct usb_device *udev,
 		hcd->driver->endpoint_disable(hcd, ep);
 }
 
+/**
+ * usb_hcd_reset_endpoint - reset host endpoint state
+ * @udev: USB device.
+ * @ep:   the endpoint to reset.
+ *
+ * Resets any host endpoint state such as the toggle bit, sequence
+ * number and current window.
+ */
+void usb_hcd_reset_endpoint(struct usb_device *udev,
+			    struct usb_host_endpoint *ep)
+{
+	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+	if (hcd->driver->endpoint_reset)
+		hcd->driver->endpoint_reset(hcd, ep);
+	else {
+		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);
+
+		usb_settoggle(udev, epnum, is_out, 0);
+		if (is_control)
+			usb_settoggle(udev, epnum, !is_out, 0);
+	}
+}
+
 /* Protect against drivers that try to unlink URBs after the device
  * is gone, by waiting until all unlinks for @udev are finished.
  * Since we don't currently track URBs by device, simply wait until
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index f750eb1ab59..e7d4479de41 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -206,6 +206,11 @@ struct hc_driver {
 	void 	(*endpoint_disable)(struct usb_hcd *hcd,
 			struct usb_host_endpoint *ep);
 
+	/* (optional) reset any endpoint state such as sequence number
+	   and current window */
+	void 	(*endpoint_reset)(struct usb_hcd *hcd,
+			struct usb_host_endpoint *ep);
+
 	/* root hub support */
 	int	(*hub_status_data) (struct usb_hcd *hcd, char *buf);
 	int	(*hub_control) (struct usb_hcd *hcd,
@@ -234,6 +239,8 @@ extern void usb_hcd_flush_endpoint(struct usb_device *udev,
 		struct usb_host_endpoint *ep);
 extern void usb_hcd_disable_endpoint(struct usb_device *udev,
 		struct usb_host_endpoint *ep);
+extern void usb_hcd_reset_endpoint(struct usb_device *udev,
+		struct usb_host_endpoint *ep);
 extern void usb_hcd_synchronize_unlinks(struct usb_device *udev);
 extern int usb_hcd_get_frame_number(struct usb_device *udev);
 
@@ -279,6 +286,13 @@ extern irqreturn_t usb_hcd_irq(int irq, void *__hcd);
 extern void usb_hc_died(struct usb_hcd *hcd);
 extern void usb_hcd_poll_rh_status(struct usb_hcd *hcd);
 
+/* The D0/D1 toggle bits ... USE WITH CAUTION (they're almost hcd-internal) */
+#define usb_gettoggle(dev, ep, out) (((dev)->toggle[out] >> (ep)) & 1)
+#define	usb_dotoggle(dev, ep, out)  ((dev)->toggle[out] ^= (1 << (ep)))
+#define usb_settoggle(dev, ep, out, bit) \
+		((dev)->toggle[out] = ((dev)->toggle[out] & ~(1 << (ep))) | \
+		 ((bit) << (ep)))
+
 /* -------------------------------------------------------------------------- */
 
 /* Enumeration is only for the hub driver, or HCD virtual root hubs */
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 30a0690f368..b6262837765 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1002,8 +1002,7 @@ int usb_clear_halt(struct usb_device *dev, int pipe)
 	 * the copy in usb-storage, for as long as we need two copies.
 	 */
 
-	/* toggle was reset by the clear */
-	usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0);
+	usb_reset_endpoint(dev, endp);
 
 	return 0;
 }
@@ -1076,6 +1075,30 @@ void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
 }
 
 /**
+ * usb_reset_endpoint - Reset an endpoint's state.
+ * @dev: the device whose endpoint is to be reset
+ * @epaddr: the endpoint's address.  Endpoint number for output,
+ *	endpoint number + USB_DIR_IN for input
+ *
+ * Resets any host-side endpoint state such as the toggle bit,
+ * sequence number or current window.
+ */
+void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
+{
+	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
+	struct usb_host_endpoint *ep;
+
+	if (usb_endpoint_out(epaddr))
+		ep = dev->ep_out[epnum];
+	else
+		ep = dev->ep_in[epnum];
+	if (ep)
+		usb_hcd_reset_endpoint(dev, ep);
+}
+EXPORT_SYMBOL_GPL(usb_reset_endpoint);
+
+
+/**
  * usb_disable_interface -- Disable all endpoints for an interface
  * @dev: the device whose interface is being disabled
  * @intf: pointer to the interface descriptor
@@ -1117,7 +1140,6 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
 		usb_disable_endpoint(dev, i, true);
 		usb_disable_endpoint(dev, i + USB_DIR_IN, true);
 	}
-	dev->toggle[0] = dev->toggle[1] = 0;
 
 	/* getting rid of interfaces will disconnect
 	 * any drivers bound to them (a key side effect)
@@ -1154,28 +1176,24 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
  * usb_enable_endpoint - Enable an endpoint for USB communications
  * @dev: the device whose interface is being enabled
  * @ep: the endpoint
- * @reset_toggle: flag to set the endpoint's toggle back to 0
+ * @reset_ep: flag to reset the endpoint state
  *
- * Resets the endpoint toggle if asked, and sets dev->ep_{in,out} pointers.
+ * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
  * For control endpoints, both the input and output sides are handled.
  */
 void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
-		bool reset_toggle)
+		bool reset_ep)
 {
 	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);
 
-	if (is_out || is_control) {
-		if (reset_toggle)
-			usb_settoggle(dev, epnum, 1, 0);
+	if (reset_ep)
+		usb_hcd_reset_endpoint(dev, ep);
+	if (is_out || is_control)
 		dev->ep_out[epnum] = ep;
-	}
-	if (!is_out || is_control) {
-		if (reset_toggle)
-			usb_settoggle(dev, epnum, 0, 0);
+	if (!is_out || is_control)
 		dev->ep_in[epnum] = ep;
-	}
 	ep->enabled = 1;
 }
 
@@ -1183,18 +1201,18 @@ void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
  * usb_enable_interface - Enable all the endpoints for an interface
  * @dev: the device whose interface is being enabled
  * @intf: pointer to the interface descriptor
- * @reset_toggles: flag to set the endpoints' toggles back to 0
+ * @reset_eps: flag to reset the endpoints' state
  *
  * Enables all the endpoints for the interface's current altsetting.
  */
 void usb_enable_interface(struct usb_device *dev,
-		struct usb_interface *intf, bool reset_toggles)
+		struct usb_interface *intf, bool reset_eps)
 {
 	struct usb_host_interface *alt = intf->cur_altsetting;
 	int i;
 
 	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
-		usb_enable_endpoint(dev, &alt->endpoint[i], reset_toggles);
+		usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
 }
 
 /**
@@ -1335,7 +1353,7 @@ EXPORT_SYMBOL_GPL(usb_set_interface);
  * This issues a standard SET_CONFIGURATION request to the device using
  * the current configuration.  The effect is to reset most USB-related
  * state in the device, including interface altsettings (reset to zero),
- * endpoint halts (cleared), and data toggle (only for bulk and interrupt
+ * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
  * endpoints).  Other usbcore state is unchanged, including bindings of
  * usb device drivers to interfaces.
  *
@@ -1343,7 +1361,7 @@ EXPORT_SYMBOL_GPL(usb_set_interface);
  * (multi-interface) devices.  Instead, the driver for each interface may
  * use usb_set_interface() on the interfaces it claims.  Be careful though;
  * some devices don't support the SET_INTERFACE request, and others won't
- * reset all the interface state (notably data toggles).  Resetting the whole
+ * reset all the interface state (notably endpoint state).  Resetting the whole
  * configuration would affect other drivers' interfaces.
  *
  * The caller must own the device lock.
@@ -1376,8 +1394,6 @@ int usb_reset_configuration(struct usb_device *dev)
 	if (retval < 0)
 		return retval;
 
-	dev->toggle[0] = dev->toggle[1] = 0;
-
 	/* re-init hc/hcd interface/endpoint state */
 	for (i = 0; i < config->desc.bNumInterfaces; i++) {
 		struct usb_interface *intf = config->interface[i];
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index dcfc072630c..7eee400d3e3 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -362,7 +362,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
 	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
 	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
 	/* ep0 maxpacket comes later, from device descriptor */
-	usb_enable_endpoint(dev, &dev->ep0, true);
+	usb_enable_endpoint(dev, &dev->ep0, false);
 	dev->can_submit = 1;
 
 	/* Save readable and stable topology id, distinguishing devices
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index 49aedb36dc1..fcb32021721 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -247,10 +247,8 @@ int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
 		USB_ENDPOINT_HALT, endp,
 		NULL, 0, 3*HZ);
 
-	/* reset the endpoint toggle */
 	if (result >= 0)
-		usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
-				usb_pipeout(pipe), 0);
+		usb_reset_endpoint(us->pusb_dev, endp);
 
 	US_DEBUGP("%s: result = %d\n", __func__, result);
 	return result;