[PATCH] usb_interface power state

This updates the handling of power state for USB interfaces.

  - Formalizes an existing invariant:  interface "power state" is a boolean:
    ON when I/O is allowed, and FREEZE otherwise.  It does so by defining
    some inlined helpers, then using them.

  - Adds a useful invariant:  the only interfaces marked active are those
    bound to non-suspended drivers.  Later patches build on this invariant.

  - Simplifies the interface driver API (and removes some error paths) by
    removing the requirement that they record power state changes during
    suspend and resume callbacks.  Now usbcore does that.

A few drivers were simplified to address that last change.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 drivers/usb/core/hub.c       |   33 +++++++++------------
 drivers/usb/core/message.c   |    1
 drivers/usb/core/usb.c       |   65 +++++++++++++++++++++++++++++++++----------
 drivers/usb/core/usb.h       |   18 +++++++++++
 drivers/usb/input/hid-core.c |    2 -
 drivers/usb/misc/usbtest.c   |   10 ------
 drivers/usb/net/pegasus.c    |    2 -
 drivers/usb/net/usbnet.c     |    2 -
 8 files changed, 85 insertions(+), 48 deletions(-)

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index e6504f3370ad..3741a990403e 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -28,6 +28,24 @@ extern void usb_major_cleanup(void);
 extern int usb_host_init(void);
 extern void usb_host_cleanup(void);
 
+/* Interfaces and their "power state" are owned by usbcore */
+
+static inline void mark_active(struct usb_interface *f)
+{
+	f->dev.power.power_state.event = PM_EVENT_ON;
+}
+
+static inline void mark_quiesced(struct usb_interface *f)
+{
+	f->dev.power.power_state.event = PM_EVENT_FREEZE;
+}
+
+static inline int is_active(struct usb_interface *f)
+{
+	return f->dev.power.power_state.event == PM_EVENT_ON;
+}
+
+
 /* for labeling diagnostics */
 extern const char *usbcore_name;