[PATCH] root hub updates (greater half)

This patch associates hub suspend and resume logic (including for root hubs)
with CONFIG_PM -- instead of CONFIG_USB_SUSPEND as before -- thereby unifying
two troublesome versions of suspend logic into just one.  It'll be easier to
keep things right from now on.

  - Now usbcore _always_ calls hcd->hub_suspend as needed, instead of
    only when USB_SUSPEND is enabled:
     * Those root hub methods are now called from hub suspend/resume;
       no more skipping between layers during device suspend/resume;
     * It now handles cases allowed by sysfs or autosuspended root hubs,
       by forcing the hub interface to resume too.

  - All devices, including virtual root hubs, now get the same treatment
    on their resume paths ... including re-activating all their interfaces.

Plus it gets rid of those stub copies of usb_{suspend,resume}_device(), and
updates the Kconfig to match the new definition of USB_SUSPEND:  it provides
(a) selective suspend, downstream from hubs; and (b) remote wakeup, upstream
from any device configuration which supports it.

This calls for minor followup patches for most HCDs (and their PCI glue).

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

 drivers/usb/core/Kconfig |   11 ++-
 drivers/usb/core/hub.c   |  163 +++++++++++++++++++++++++----------------------
 2 files changed, 97 insertions(+), 77 deletions(-)

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 1a9ff6184943..ff03184da403 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -61,14 +61,17 @@ config USB_DYNAMIC_MINORS
           If you are unsure about this, say N here.
 
 config USB_SUSPEND
-        bool "USB suspend/resume (EXPERIMENTAL)"
+        bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)"
         depends on USB && PM && EXPERIMENTAL
         help
           If you say Y here, you can use driver calls or the sysfs
           "power/state" file to suspend or resume individual USB
-          peripherals.  There are many related features, such as
-          remote wakeup and driver-specific suspend processing, that
-          may not yet work as expected.
+          peripherals.
+
+          Also, USB "remote wakeup" signaling is supported, whereby some
+          USB devices (like keyboards and network adapters) can wake up
+          their parent hub.  That wakeup cascades up the USB tree, and
+          could wake the system from states like suspend-to-RAM.
 
           If you are unsure about this, say N here.