USB: address-0 handling during device initialization

This patch (as947) changes the device initialization and enumeration
code in hub.c; now udev->devnum will be set to 0 while the device is
being accessed at address 0.  Until now this wasn't needed because the
address value was passed as part of urb->pipe; without that field the
device address must be stored elsewhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 14 insertions, 11 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c8a01f66df7..34be27a6cbb 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1481,6 +1481,7 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
                 case 0:
                         /* TRSTRCY = 10 ms; plus some extra */
                         msleep(10 + 40);
+                        udev->devnum = 0;       /* Device now at address 0 */
                         /* FALL THROUGH */
                 case -ENOTCONN:
                 case -ENODEV:
@@ -2005,20 +2006,21 @@ static void ep0_reinit(struct usb_device *udev)
 #define usb_sndaddr0pipe()      (PIPE_CONTROL << 30)
 #define usb_rcvaddr0pipe()      ((PIPE_CONTROL << 30) | USB_DIR_IN)
 
-static int hub_set_address(struct usb_device *udev)
+static int hub_set_address(struct usb_device *udev, int devnum)
 {
         int retval;
 
-        if (udev->devnum == 0)
+        if (devnum <= 1)
                 return -EINVAL;
         if (udev->state == USB_STATE_ADDRESS)
                 return 0;
         if (udev->state != USB_STATE_DEFAULT)
                 return -EINVAL;
         retval = usb_control_msg(udev, usb_sndaddr0pipe(),
-                USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
+                USB_REQ_SET_ADDRESS, 0, devnum, 0,
                 NULL, 0, USB_CTRL_SET_TIMEOUT);
         if (retval == 0) {
+                udev->devnum = devnum;  /* Device now using proper address */
                 usb_set_device_state(udev, USB_STATE_ADDRESS);
                 ep0_reinit(udev);
         }
@@ -2045,6 +2047,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
         unsigned                delay = HUB_SHORT_RESET_TIME;
         enum usb_device_speed   oldspeed = udev->speed;
         char                    *speed, *type;
+        int                     devnum = udev->devnum;
 
         /* root hub ports have a slightly longer reset period
          * (from USB 2.0 spec, section 7.1.7.5)
@@ -2074,7 +2077,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
                 goto fail;
         }
         oldspeed = udev->speed;
-  
+
         /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
          * it's fixed size except for full speed devices.
          * For Wireless USB devices, ep0 max packet is always 512 (tho
@@ -2115,7 +2118,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
         dev_info (&udev->dev,
                   "%s %s speed %sUSB device using %s and address %d\n",
                   (udev->config) ? "reset" : "new", speed, type,
-                  udev->bus->controller->driver->name, udev->devnum);
+                  udev->bus->controller->driver->name, devnum);
 
         /* Set up TT records, if needed  */
         if (hdev->tt) {
@@ -2202,7 +2205,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
                 }
 
                 for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
-                        retval = hub_set_address(udev);
+                        retval = hub_set_address(udev, devnum);
                         if (retval >= 0)
                                 break;
                         msleep(200);
@@ -2210,7 +2213,7 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
                 if (retval < 0) {
                         dev_err(&udev->dev,
                                 "device not accepting address %d, error %d\n",
-                                udev->devnum, retval);
+                                devnum, retval);
                         goto fail;
                 }
  
@@ -2263,8 +2266,10 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
         retval = 0;
 
 fail:
-        if (retval)
+        if (retval) {
                 hub_port_disable(hub, port1, 0);
+                udev->devnum = devnum;  /* for disconnect processing */
+        }
         mutex_unlock(&usb_address0_mutex);
         return retval;
 }
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 1a64a6a850f..1acca8696bc 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -284,9 +284,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 
         if (!urb || urb->hcpriv || !urb->complete)
                 return -EINVAL;
-        if (!(dev = urb->dev) ||
-            (dev->state < USB_STATE_DEFAULT) ||
-            (!dev->bus) || (dev->devnum <= 0))
+        if (!(dev = urb->dev) || dev->state < USB_STATE_DEFAULT)
                 return -ENODEV;
         if (dev->bus->controller->power.power_state.event != PM_EVENT_ON
                         || dev->state == USB_STATE_SUSPENDED)