wusb: reset WUSB devices with SetAddress(0)

Using a Reset Device IE to reset a WUSB device is too heavyweight as it
causes the devcie to disconnect (which the USB stack does not expect and
cannot handle).  Instead, do a SetAddress(0); SetAddress(AuthAddr) for
authenticated devices.

Unauthenticated devices will not be reset and the stack will have to rely
on the device timing out after TrustTimeout and disconnecting.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

4 files changed, 25 insertions, 122 deletions

diff --git a/drivers/usb/wusbcore/devconnect.c b/drivers/usb/wusbcore/devconnect.c
index f45d777..c01c7a8 100644
--- a/drivers/usb/wusbcore/devconnect.c
+++ b/drivers/usb/wusbcore/devconnect.c
@@ -57,9 +57,6 @@
  *                              Called by notif.c:wusb_handle_dn_connect()
  *                              when a DN_Connect is received.
  *
- *   wusbhc_devconnect_auth()   Called by rh.c:wusbhc_rh_port_reset() when
- *                              doing the device connect sequence.
- *
  *     wusb_devconnect_acked()  Ack done, release resources.
  *
  *   wusb_handle_dn_alive()     Called by notif.c:wusb_handle_dn()
@@ -69,9 +66,6 @@
  *                              process a disconenct request from a
  *                              device.
  *
- *   wusb_dev_reset()           Called by rh.c:wusbhc_rh_port_reset() when
- *                              resetting a device.
- *
  *   __wusb_dev_disable()       Called by rh.c:wusbhc_rh_clear_port_feat() when
  *                              disabling a port.
  *
@@ -366,12 +360,10 @@ void wusbhc_devconnect_ack(struct wusbhc *wusbhc, struct wusb_dn_connect *dnc,
 	port->wusb_dev = wusb_dev;
 	port->status |= USB_PORT_STAT_CONNECTION;
 	port->change |= USB_PORT_STAT_C_CONNECTION;
-	port->reset_count = 0;
 	/* Now the port status changed to connected; khubd will
 	 * pick the change up and try to reset the port to bring it to
 	 * the enabled state--so this process returns up to the stack
-	 * and it calls back into wusbhc_rh_port_reset() who will call
-	 * devconnect_auth().
+	 * and it calls back into wusbhc_rh_port_reset().
 	 */
 error_unlock:
 	mutex_unlock(&wusbhc->mutex);
@@ -413,9 +405,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc,
 		wusb_dev_put(wusb_dev);
 	}
 	port->wusb_dev = NULL;
-	/* don't reset the reset_count to zero or wusbhc_rh_port_reset will get
-	 * confused! We only reset to zero when we connect a new device.
-	 */
 
 	/* After a device disconnects, change the GTK (see [WUSB]
 	 * section 6.2.11.2). */
@@ -429,39 +418,6 @@ static void __wusbhc_dev_disconnect(struct wusbhc *wusbhc,
 }
 
 /*
- * Authenticate a device into the WUSB Cluster
- *
- * Called from the Root Hub code (rh.c:wusbhc_rh_port_reset()) when
- * asking for a reset on a port that is not enabled (ie: first connect
- * on the port).
- *
- * Performs the 4way handshake to allow the device to comunicate w/ the
- * WUSB Cluster securely; once done, issue a request to the device for
- * it to change to address 0.
- *
- * This mimics the reset step of Wired USB that once resetting a
- * device, leaves the port in enabled state and the dev with the
- * default address (0).
- *
- * WUSB1.0[7.1.2]
- *
- * @port_idx: port where the change happened--This is the index into
- *            the wusbhc port array, not the USB port number.
- */
-int wusbhc_devconnect_auth(struct wusbhc *wusbhc, u8 port_idx)
-{
-	struct device *dev = wusbhc->dev;
-	struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);
-
-	d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);
-	port->status &= ~USB_PORT_STAT_RESET;
-	port->status |= USB_PORT_STAT_ENABLE;
-	port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;
-	d_fnend(3, dev, "(%p, %u) = 0\n", wusbhc, port_idx);
-	return 0;
-}
-
-/*
  * Refresh the list of keep alives to emit in the MMC
  *
  * Some devices don't respond to keep alives unless they've been
@@ -662,60 +618,6 @@ static void wusbhc_handle_dn_disconnect(struct wusbhc *wusbhc, struct wusb_dev *
 }
 
 /*
- * Reset a WUSB device on a HWA
- *
- * @wusbhc
- * @port_idx   Index of the port where the device is
- *
- * In Wireless USB, a reset is more or less equivalent to a full
- * disconnect; so we just do a full disconnect and send the device a
- * Device Reset IE (WUSB1.0[7.5.11]) giving it a few millisecs (6 MMCs).
- *
- * @wusbhc should be refcounted and unlocked
- */
-int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port_idx)
-{
-	int result;
-	struct device *dev = wusbhc->dev;
-	struct wusb_dev *wusb_dev;
-	struct wuie_reset *ie;
-
-	d_fnstart(3, dev, "(%p, %u)\n", wusbhc, port_idx);
-	mutex_lock(&wusbhc->mutex);
-	result = 0;
-	wusb_dev = wusb_port_by_idx(wusbhc, port_idx)->wusb_dev;
-	if (wusb_dev == NULL) {
-		/* reset no device? ignore */
-		dev_dbg(dev, "RESET: no device at port %u, ignoring\n",
-			port_idx);
-		goto error_unlock;
-	}
-	result = -ENOMEM;
-	ie = kzalloc(sizeof(*ie), GFP_KERNEL);
-	if (ie == NULL)
-		goto error_unlock;
-	ie->hdr.bLength = sizeof(ie->hdr) + sizeof(ie->CDID);
-	ie->hdr.bIEIdentifier = WUIE_ID_RESET_DEVICE;
-	ie->CDID = wusb_dev->cdid;
-	result = wusbhc_mmcie_set(wusbhc, 0xff, 6, &ie->hdr);
-	if (result < 0) {
-		dev_err(dev, "RESET: cant's set MMC: %d\n", result);
-		goto error_kfree;
-	}
-	__wusbhc_dev_disconnect(wusbhc, wusb_port_by_idx(wusbhc, port_idx));
-
-	/* 120ms, hopefully 6 MMCs (FIXME) */
-	msleep(120);
-	wusbhc_mmcie_rm(wusbhc, &ie->hdr);
-error_kfree:
-	kfree(ie);
-error_unlock:
-	mutex_unlock(&wusbhc->mutex);
-	d_fnend(3, dev, "(%p, %u) = %d\n", wusbhc, port_idx, result);
-	return result;
-}
-
-/*
  * Handle a Device Notification coming a host
  *
  * The Device Notification comes from a host (HWA, DWA or WHCI)
diff --git a/drivers/usb/wusbcore/rh.c b/drivers/usb/wusbcore/rh.c
index 267a643..1c73319 100644
--- a/drivers/usb/wusbcore/rh.c
+++ b/drivers/usb/wusbcore/rh.c
@@ -77,13 +77,17 @@
 /*
  * Reset a fake port
  *
- * This can be called to reset a port from any other state or to reset
- * it when connecting. In Wireless USB they are different; when doing
- * a new connect that involves going over the authentication. When
- * just reseting, its a different story.
+ * Using a Reset Device IE is too heavyweight as it causes the device
+ * to enter the UnConnected state and leave the cluster, this can mean
+ * that when the device reconnects it is connected to a different fake
+ * port.
  *
- * The Linux USB stack resets a port twice before it considers it
- * enabled, so we have to detect and ignore that.
+ * Instead, reset authenticated devices with a SetAddress(0), followed
+ * by a SetAddresss(AuthAddr).
+ *
+ * For unauthenticated devices just pretend to reset but do nothing.
+ * If the device initialization continues to fail it will eventually
+ * time out after TrustTimeout and enter the UnConnected state.
  *
  * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
  *
@@ -97,20 +101,20 @@ static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx)
 {
 	int result = 0;
 	struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);
+	struct wusb_dev *wusb_dev = port->wusb_dev;
+
+	port->status |= USB_PORT_STAT_RESET;
+	port->change |= USB_PORT_STAT_C_RESET;
 
-	d_fnstart(3, wusbhc->dev, "(wusbhc %p port_idx %u)\n",
-		  wusbhc, port_idx);
-	if (port->reset_count == 0) {
-		wusbhc_devconnect_auth(wusbhc, port_idx);
-		port->reset_count++;
-	} else if (port->reset_count == 1)
-		/* see header */
-		d_printf(2, wusbhc->dev, "Ignoring second reset on port_idx "
-			"%u\n", port_idx);
+	if (wusb_dev->addr & WUSB_DEV_ADDR_UNAUTH)
+		result = 0;
 	else
-		result = wusbhc_dev_reset(wusbhc, port_idx);
-	d_fnend(3, wusbhc->dev, "(wusbhc %p port_idx %u) = %d\n",
-		wusbhc, port_idx, result);
+		result = wusb_dev_update_address(wusbhc, wusb_dev);
+
+	port->status &= ~USB_PORT_STAT_RESET;
+	port->status |= USB_PORT_STAT_ENABLE;
+	port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;	
+
 	return result;
 }
 
diff --git a/drivers/usb/wusbcore/security.c b/drivers/usb/wusbcore/security.c
index a101cad..ac00640 100644
--- a/drivers/usb/wusbcore/security.c
+++ b/drivers/usb/wusbcore/security.c
@@ -338,8 +338,7 @@ static void hs_printk(unsigned level, struct device *dev,
  * Before the device's address (as known by it) was usb_dev->devnum |
  * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
  */
-static int wusb_dev_update_address(struct wusbhc *wusbhc,
-				   struct wusb_dev *wusb_dev)
+int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 {
 	int result = -ENOMEM;
 	struct usb_device *usb_dev = wusb_dev->usb_dev;
diff --git a/drivers/usb/wusbcore/wusbhc.h b/drivers/usb/wusbcore/wusbhc.h
index b9bdf5a..8fef934 100644
--- a/drivers/usb/wusbcore/wusbhc.h
+++ b/drivers/usb/wusbcore/wusbhc.h
@@ -154,7 +154,6 @@ struct wusb_port {
 	u16 status;
 	u16 change;
 	struct wusb_dev *wusb_dev;	/* connected device's info */
-	unsigned reset_count;
 	u32 ptk_tkid;
 };
 
@@ -387,10 +386,8 @@ extern void wusbhc_devconnect_destroy(struct wusbhc *);
 extern int wusbhc_devconnect_start(struct wusbhc *wusbhc,
 				   const struct wusb_ckhdid *chid);
 extern void wusbhc_devconnect_stop(struct wusbhc *wusbhc);
-extern int wusbhc_devconnect_auth(struct wusbhc *, u8);
 extern void wusbhc_handle_dn(struct wusbhc *, u8 srcaddr,
 			     struct wusb_dn_hdr *dn_hdr, size_t size);
-extern int wusbhc_dev_reset(struct wusbhc *wusbhc, u8 port);
 extern void __wusbhc_dev_disable(struct wusbhc *wusbhc, u8 port);
 extern int wusb_usb_ncb(struct notifier_block *nb, unsigned long val,
 			void *priv);
@@ -436,6 +433,7 @@ extern void wusb_dev_sec_rm(struct wusb_dev *) ;
 extern int wusb_dev_4way_handshake(struct wusbhc *, struct wusb_dev *,
 				   struct wusb_ckhdid *ck);
 void wusbhc_gtk_rekey(struct wusbhc *wusbhc);
+int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev);
 
 
 /* WUSB Cluster ID handling */