[PATCH] root hub changes (lesser half)

This patch collects various small updates related to root hubs, to shrink
later patches which build on them.

  - For root hub suspend/resume support:
     * Make the existing usb_hcd_resume_root_hub() routine respect pmcore
       locking, exporting and using the dpm_runtime_resume() method.
     * Add a new usb_hcd_suspend_root_hub() to pair with that routine.
       (Essential to make OHCI autosuspend behave again...)
     * HC_SUSPENDED by itself only refers to the root hub's downstream ports.
       So let HCDs see root hub URBs unless the parent device is suspended.

  - Remove an assertion we no longer need (and now, also don't want).

  - Generic suspend/resume updates to work better with swsusp.
     * Ignore the FREEZE vs SUSPEND distinction for hardware; trying to
       use it breaks the swsusp snapshots it's supposed to help (sigh).
     * On resume, mark devices as resumed right away, but then
       do nothing else if the device is marked NOTATTACHED.

These changes shouldn't be very noticable by themselves.

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

 drivers/base/power/runtime.c |    1
 drivers/usb/core/hcd.c       |   64 ++++++++++++++++++++++++++++++++++++++-----
 drivers/usb/core/hcd.h       |    1
 drivers/usb/core/hub.c       |   45 ++++++++++++++++++++++++------
 drivers/usb/core/usb.c       |   20 +++++++++----
 drivers/usb/core/usb.h       |    1
 6 files changed, 111 insertions(+), 21 deletions(-)

1 files changed, 37 insertions, 8 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 660064466791..3c8d8d1f993c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -449,11 +449,18 @@ static void hub_power_on(struct usb_hub *hub)
         msleep(max(pgood_delay, (unsigned) 100));
 }
 
-static void hub_quiesce(struct usb_hub *hub)
+static inline void __hub_quiesce(struct usb_hub *hub)
 {
-        /* stop khubd and related activity */
+        /* (nonblocking) khubd and related activity won't re-trigger */
         hub->quiescing = 1;
         hub->activating = 0;
+        hub->resume_root_hub = 0;
+}
+
+static void hub_quiesce(struct usb_hub *hub)
+{
+        /* (blocking) stop khubd and related activity */
+        __hub_quiesce(hub);
         usb_kill_urb(hub->urb);
         if (hub->has_indicators)
                 cancel_delayed_work(&hub->leds);
@@ -467,6 +474,7 @@ static void hub_activate(struct usb_hub *hub)
 
         hub->quiescing = 0;
         hub->activating = 1;
+        hub->resume_root_hub = 0;
         status = usb_submit_urb(hub->urb, GFP_NOIO);
         if (status < 0)
                 dev_err(hub->intfdev, "activate --> %d\n", status);
@@ -1959,6 +1967,18 @@ static int hub_resume(struct usb_interface *intf)
         return 0;
 }
 
+void usb_suspend_root_hub(struct usb_device *hdev)
+{
+        struct usb_hub *hub = hdev_to_hub(hdev);
+
+        /* This also makes any led blinker stop retriggering.  We're called
+         * from irq, so the blinker might still be scheduled.  Caller promises
+         * that the root hub status URB will be canceled.
+         */
+        __hub_quiesce(hub);
+        mark_quiesced(to_usb_interface(hub->intfdev));
+}
+
 void usb_resume_root_hub(struct usb_device *hdev)
 {
         struct usb_hub *hub = hdev_to_hub(hdev);
@@ -2616,21 +2636,30 @@ static void hub_events(void)
                 intf = to_usb_interface(hub->intfdev);
                 hub_dev = &intf->dev;
 
-                dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
+                i = hub->resume_root_hub;
+
+                dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x%s\n",
                                 hdev->state, hub->descriptor
                                         ? hub->descriptor->bNbrPorts
                                         : 0,
                                 /* NOTE: expects max 15 ports... */
                                 (u16) hub->change_bits[0],
-                                (u16) hub->event_bits[0]);
+                                (u16) hub->event_bits[0],
+                                i ? ", resume root" : "");
 
                 usb_get_intf(intf);
-                i = hub->resume_root_hub;
                 spin_unlock_irq(&hub_event_lock);
 
-                /* Is this is a root hub wanting to be resumed? */
-                if (i)
-                        usb_resume_device(hdev);
+                /* Is this is a root hub wanting to reactivate the downstream
+                 * ports?  If so, be sure the interface resumes even if its
+                 * stub "device" node was never suspended.
+                 */
+                if (i) {
+                        extern void dpm_runtime_resume(struct device *);
+
+                        dpm_runtime_resume(&hdev->dev);
+                        dpm_runtime_resume(&intf->dev);
+                }
 
                 /* Lock the device, then check to see if we were
                  * disconnected while waiting for the lock to succeed. */