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-rw-r--r--drivers/usb/core/driver.c31
-rw-r--r--include/linux/usb.h3
2 files changed, 31 insertions, 3 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index ed1cc8530a9..637b2bea556 100644
--- a/drivers/usb/core/driver.c
+++ b/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/include/linux/usb.h b/include/linux/usb.h
index 0924cd9c30f..94ac74aba6b 100644
--- a/include/linux/usb.h
+++ b/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 */