From 65fce4d63756c1ad878e93c696e02f96faa43ddf Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Tue, 12 Aug 2008 14:33:59 -0400
Subject: [PATCH] --- yaml --- r: 108977 b: refs/heads/master c:
 55151d7daba185f94e9dc561a5a2ba36b5f647dd h: refs/heads/master i:   108975:
 c29b5cf30201f9c7c25fa7df27db8f46207baf41 v: v3

---
 [refs]                          |  2 +-
 trunk/drivers/usb/core/driver.c | 31 ++++++++++++++++++++++++++++---
 trunk/include/linux/usb.h       |  3 +++
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index f5f4d4e9d455..7536e132239e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 65605ae8e587d714f73e674369bc4cd5a1e53a9b
+refs/heads/master: 55151d7daba185f94e9dc561a5a2ba36b5f647dd
diff --git a/trunk/drivers/usb/core/driver.c b/trunk/drivers/usb/core/driver.c
index ed1cc8530a93..637b2bea5563 100644
--- a/trunk/drivers/usb/core/driver.c
+++ b/trunk/drivers/usb/core/driver.c
@@ -230,6 +230,13 @@ static int usb_probe_interface(struct device *dev)
 		 */
 		intf->pm_usage_cnt = !(driver->supports_autosuspend);
 
+		/* Carry out a deferred switch to altsetting 0 */
+		if (intf->needs_altsetting0) {
+			usb_set_interface(udev, intf->altsetting[0].
+					desc.bInterfaceNumber, 0);
+			intf->needs_altsetting0 = 0;
+		}
+
 		error = driver->probe(intf, id);
 		if (error) {
 			mark_quiesced(intf);
@@ -266,8 +273,17 @@ static int usb_unbind_interface(struct device *dev)
 
 	driver->disconnect(intf);
 
-	/* reset other interface state */
-	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
+	/* Reset other interface state.
+	 * We cannot do a Set-Interface if the device is suspended or
+	 * if it is prepared for a system sleep (since installing a new
+	 * altsetting means creating new endpoint device entries).
+	 * When either of these happens, defer the Set-Interface.
+	 */
+	if (!error && intf->dev.power.status == DPM_ON)
+		usb_set_interface(udev, intf->altsetting[0].
+				desc.bInterfaceNumber, 0);
+	else
+		intf->needs_altsetting0 = 1;
 	usb_set_intfdata(intf, NULL);
 
 	intf->condition = USB_INTERFACE_UNBOUND;
@@ -975,8 +991,17 @@ static int usb_resume_interface(struct usb_device *udev,
 		goto done;
 
 	/* Can't resume it if it doesn't have a driver. */
-	if (intf->condition == USB_INTERFACE_UNBOUND)
+	if (intf->condition == USB_INTERFACE_UNBOUND) {
+
+		/* Carry out a deferred switch to altsetting 0 */
+		if (intf->needs_altsetting0 &&
+				intf->dev.power.status == DPM_ON) {
+			usb_set_interface(udev, intf->altsetting[0].
+					desc.bInterfaceNumber, 0);
+			intf->needs_altsetting0 = 0;
+		}
 		goto done;
+	}
 
 	/* Don't resume if the interface is marked for rebinding */
 	if (intf->needs_binding)
diff --git a/trunk/include/linux/usb.h b/trunk/include/linux/usb.h
index 0924cd9c30f6..94ac74aba6b6 100644
--- a/trunk/include/linux/usb.h
+++ b/trunk/include/linux/usb.h
@@ -110,6 +110,8 @@ enum usb_interface_condition {
  * @sysfs_files_created: sysfs attributes exist
  * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
  *	capability during autosuspend.
+ * @needs_altsetting0: flag set when a set-interface request for altsetting 0
+ *	has been deferred.
  * @needs_binding: flag set when the driver should be re-probed or unbound
  *	following a reset or suspend operation it doesn't support.
  * @dev: driver model's view of this device
@@ -162,6 +164,7 @@ struct usb_interface {
 	unsigned is_active:1;		/* the interface is not suspended */
 	unsigned sysfs_files_created:1;	/* the sysfs attributes exist */
 	unsigned needs_remote_wakeup:1;	/* driver requires remote wakeup */
+	unsigned needs_altsetting0:1;	/* switch to altsetting 0 is pending */
 	unsigned needs_binding:1;	/* needs delayed unbind/rebind */
 
 	struct device dev;		/* interface specific device info */