USB: Fix connected device switch to Inactive state.
Sarah Sharp [Wed, 13 Mar 2013 17:59:21 +0000 (10:59 -0700)]
[This is upstream commit d3b9d7a9051d7024a93c76a84b2f84b3b66ad6d5.
It needs to be backported to kernels as old as 3.2, because it fixes the
buggy commit 9dbcaec830cd97f44a0b91b315844e0d7144746b "USB: Handle warm
reset failure on empty port."]

A USB 3.0 device can transition to the Inactive state if a U1 or U2 exit
transition fails.  The current code in hub_events simply issues a warm
reset, but does not call any pre-reset or post-reset driver methods (or
unbind/rebind drivers without them).  Therefore the drivers won't know
their device has just been reset.

hub_events should instead call usb_reset_device.  This means
hub_port_reset now needs to figure out whether it should issue a warm
reset or a hot reset.

Remove the FIXME note about needing disconnect() for a NOTATTACHED
device.  This patch fixes that.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hub.c

index 727c784..49b139c 100644 (file)
@@ -2274,7 +2274,6 @@ static void hub_port_finish_reset(struct usb_hub *hub, int port1,
        case -ENODEV:
                clear_port_feature(hub->hdev,
                                port1, USB_PORT_FEAT_C_RESET);
-               /* FIXME need disconnect() for NOTATTACHED device */
                if (hub_is_superspeed(hub->hdev)) {
                        clear_port_feature(hub->hdev, port1,
                                        USB_PORT_FEAT_C_BH_PORT_RESET);
@@ -2308,6 +2307,18 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
                 * Some companion controllers don't like it when they mix.
                 */
                down_read(&ehci_cf_port_reset_rwsem);
+       } else if (!warm) {
+               /*
+                * If the caller hasn't explicitly requested a warm reset,
+                * double check and see if one is needed.
+                */
+               status = hub_port_status(hub, port1,
+                                       &portstatus, &portchange);
+               if (status < 0)
+                       goto done;
+
+               if (hub_port_warm_reset_required(hub, portstatus))
+                       warm = true;
        }
 
        /* Reset the port */
@@ -3866,12 +3877,21 @@ static void hub_events(void)
                         */
                        if (hub_port_warm_reset_required(hub, portstatus)) {
                                int status;
+                               struct usb_device *udev =
+                                       hub->hdev->children[i - 1];
 
                                dev_dbg(hub_dev, "warm reset port %d\n", i);
-                               status = hub_port_reset(hub, i, NULL,
-                                               HUB_BH_RESET_TIME, true);
-                               if (status < 0)
-                                       hub_port_disable(hub, i, 1);
+                               if (!udev) {
+                                       status = hub_port_reset(hub, i,
+                                                       NULL, HUB_BH_RESET_TIME,
+                                                       true);
+                                       if (status < 0)
+                                               hub_port_disable(hub, i, 1);
+                               } else {
+                                       usb_lock_device(udev);
+                                       status = usb_reset_device(udev);
+                                       usb_unlock_device(udev);
+                               }
                                connect_change = 0;
                        }