3 files changed, 140 insertions, 87 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 0da23732e807..1180c157b717 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -519,119 +519,120 @@ error:
 /*-------------------------------------------------------------------------*/
 
 /*
- * Root Hub interrupt transfers are synthesized with a timer.
- * Completions are called in_interrupt() but not in_irq().
+ * Root Hub interrupt transfers are polled using a timer if the
+ * driver requests it; otherwise the driver is responsible for
+ * calling usb_hcd_poll_rh_status() when an event occurs.
  *
- * Note: some root hubs (including common UHCI based designs) can't
- * correctly issue port change IRQs.  They're the ones that _need_ a
- * timer; most other root hubs don't.  Some systems could save a
- * lot of battery power by eliminating these root hub timer IRQs.
+ * Completions are called in_interrupt(), but they may or may not
+ * be in_irq().
  */
+void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
+{
+        struct urb      *urb;
+        int             length;
+        unsigned long   flags;
+        char            buffer[4];      /* Any root hubs with > 31 ports? */
 
-static void rh_report_status (unsigned long ptr);
+        if (!hcd->uses_new_polling && !hcd->status_urb)
+                return;
 
-static int rh_status_urb (struct usb_hcd *hcd, struct urb *urb) 
-{
-        int     len = 1 + (urb->dev->maxchild / 8);
+        length = hcd->driver->hub_status_data(hcd, buffer);
+        if (length > 0) {
 
-        /* rh_timer protected by hcd_data_lock */
-        if (hcd->rh_timer.data || urb->transfer_buffer_length < len) {
-                dev_dbg (hcd->self.controller,
-                                "not queuing rh status urb, stat %d\n",
-                                urb->status);
-                return -EINVAL;
+                /* try to complete the status urb */
+                local_irq_save (flags);
+                spin_lock(&hcd_root_hub_lock);
+                urb = hcd->status_urb;
+                if (urb) {
+                        spin_lock(&urb->lock);
+                        if (urb->status == -EINPROGRESS) {
+                                hcd->poll_pending = 0;
+                                hcd->status_urb = NULL;
+                                urb->status = 0;
+                                urb->hcpriv = NULL;
+                                urb->actual_length = length;
+                                memcpy(urb->transfer_buffer, buffer, length);
+                        } else          /* urb has been unlinked */
+                                length = 0;
+                        spin_unlock(&urb->lock);
+                } else
+                        length = 0;
+                spin_unlock(&hcd_root_hub_lock);
+
+                /* local irqs are always blocked in completions */
+                if (length > 0)
+                        usb_hcd_giveback_urb (hcd, urb, NULL);
+                else
+                        hcd->poll_pending = 1;
+                local_irq_restore (flags);
         }
 
-        init_timer (&hcd->rh_timer);
-        hcd->rh_timer.function = rh_report_status;
-        hcd->rh_timer.data = (unsigned long) urb;
-        /* USB 2.0 spec says 256msec; this is close enough */
-        hcd->rh_timer.expires = jiffies + HZ/4;
-        add_timer (&hcd->rh_timer);
-        urb->hcpriv = hcd;      /* nonzero to indicate it's queued */
-        return 0;
+        /* The USB 2.0 spec says 256 ms.  This is close enough and won't
+         * exceed that limit if HZ is 100. */
+        if (hcd->uses_new_polling ? hcd->poll_rh :
+                        (length == 0 && hcd->status_urb != NULL))
+                mod_timer (&hcd->rh_timer, jiffies + msecs_to_jiffies(250));
 }
+EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
 
 /* timer callback */
+static void rh_timer_func (unsigned long _hcd)
+{
+        usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
+}
+
+/*-------------------------------------------------------------------------*/
 
-static void rh_report_status (unsigned long ptr)
+static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
 {
-        struct urb      *urb;
-        struct usb_hcd  *hcd;
-        int             length = 0;
+        int             retval;
         unsigned long   flags;
+        int             len = 1 + (urb->dev->maxchild / 8);
 
-        urb = (struct urb *) ptr;
-        local_irq_save (flags);
-        spin_lock (&urb->lock);
+        spin_lock_irqsave (&hcd_root_hub_lock, flags);
+        if (urb->status != -EINPROGRESS)        /* already unlinked */
+                retval = urb->status;
+        else if (hcd->status_urb || urb->transfer_buffer_length < len) {
+                dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
+                retval = -EINVAL;
+        } else {
+                hcd->status_urb = urb;
+                urb->hcpriv = hcd;      /* indicate it's queued */
 
-        /* do nothing if the urb's been unlinked */
-        if (!urb->dev
-                        || urb->status != -EINPROGRESS
-                        || (hcd = urb->dev->bus->hcpriv) == NULL) {
-                spin_unlock (&urb->lock);
-                local_irq_restore (flags);
-                return;
-        }
+                if (!hcd->uses_new_polling)
+                        mod_timer (&hcd->rh_timer, jiffies +
+                                        msecs_to_jiffies(250));
 
-        /* complete the status urb, or retrigger the timer */
-        spin_lock (&hcd_data_lock);
-        if (urb->dev->state == USB_STATE_CONFIGURED) {
-                length = hcd->driver->hub_status_data (
-                                        hcd, urb->transfer_buffer);
-                if (length > 0) {
-                        hcd->rh_timer.data = 0;
-                        urb->actual_length = length;
-                        urb->status = 0;
-                        urb->hcpriv = NULL;
-                } else
-                        mod_timer (&hcd->rh_timer, jiffies + HZ/4);
+                /* If a status change has already occurred, report it ASAP */
+                else if (hcd->poll_pending)
+                        mod_timer (&hcd->rh_timer, jiffies);
+                retval = 0;
         }
-        spin_unlock (&hcd_data_lock);
-        spin_unlock (&urb->lock);
-
-        /* local irqs are always blocked in completions */
-        if (length > 0)
-                usb_hcd_giveback_urb (hcd, urb, NULL);
-        local_irq_restore (flags);
+        spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
+        return retval;
 }
 
-/*-------------------------------------------------------------------------*/
-
 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
 {
-        if (usb_pipeint (urb->pipe)) {
-                int             retval;
-                unsigned long   flags;
-
-                spin_lock_irqsave (&hcd_data_lock, flags);
-                retval = rh_status_urb (hcd, urb);
-                spin_unlock_irqrestore (&hcd_data_lock, flags);
-                return retval;
-        }
+        if (usb_pipeint (urb->pipe))
+                return rh_queue_status (hcd, urb);
         if (usb_pipecontrol (urb->pipe))
                 return rh_call_control (hcd, urb);
-        else
-                return -EINVAL;
+        return -EINVAL;
 }
 
 /*-------------------------------------------------------------------------*/
 
+/* Asynchronous unlinks of root-hub control URBs are legal, but they
+ * don't do anything.  Status URB unlinks must be made in process context
+ * with interrupts enabled.
+ */
 static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
 {
-        unsigned long   flags;
-
-        /* note:  always a synchronous unlink */
-        if ((unsigned long) urb == hcd->rh_timer.data) {
-                del_timer_sync (&hcd->rh_timer);
-                hcd->rh_timer.data = 0;
-
-                local_irq_save (flags);
-                urb->hcpriv = NULL;
-                usb_hcd_giveback_urb (hcd, urb, NULL);
-                local_irq_restore (flags);
+        if (usb_pipeendpoint(urb->pipe) == 0) { /* Control URB */
+                if (in_interrupt())
+                        return 0;               /* nothing to do */
 
-        } else if (usb_pipeendpoint(urb->pipe) == 0) {
                 spin_lock_irq(&urb->lock);      /* from usb_kill_urb */
                 ++urb->reject;
                 spin_unlock_irq(&urb->lock);
@@ -642,8 +643,22 @@ static int usb_rh_urb_dequeue (struct usb_hcd *hcd, struct urb *urb)
                 spin_lock_irq(&urb->lock);
                 --urb->reject;
                 spin_unlock_irq(&urb->lock);
-        } else
-                return -EINVAL;
+
+        } else {                                /* Status URB */
+                if (!hcd->uses_new_polling)
+                        del_timer_sync (&hcd->rh_timer);
+                local_irq_disable ();
+                spin_lock (&hcd_root_hub_lock);
+                if (urb == hcd->status_urb) {
+                        hcd->status_urb = NULL;
+                        urb->hcpriv = NULL;
+                } else
+                        urb = NULL;             /* wasn't fully queued */
+                spin_unlock (&hcd_root_hub_lock);
+                if (urb)
+                        usb_hcd_giveback_urb (hcd, urb, NULL);
+                local_irq_enable ();
+        }
 
         return 0;
 }
@@ -885,6 +900,16 @@ int usb_hcd_register_root_hub (struct usb_device *usb_dev, struct usb_hcd *hcd)
 }
 EXPORT_SYMBOL_GPL(usb_hcd_register_root_hub);
 
+void usb_enable_root_hub_irq (struct usb_bus *bus)
+{
+        struct usb_hcd *hcd;
+
+        hcd = container_of (bus, struct usb_hcd, self);
+        if (hcd->driver->hub_irq_enable && !hcd->poll_rh &&
+                        hcd->state != HC_STATE_HALT)
+                hcd->driver->hub_irq_enable (hcd);
+}
+
 
 /*-------------------------------------------------------------------------*/
 
@@ -1348,7 +1373,8 @@ hcd_endpoint_disable (struct usb_device *udev, struct usb_host_endpoint *ep)
 
         hcd = udev->bus->hcpriv;
 
-        WARN_ON (!HC_IS_RUNNING (hcd->state) && hcd->state != HC_STATE_HALT);
+        WARN_ON (!HC_IS_RUNNING (hcd->state) && hcd->state != HC_STATE_HALT &&
+                        udev->state != USB_STATE_NOTATTACHED);
 
         local_irq_disable ();
 
@@ -1612,6 +1638,8 @@ void usb_hc_died (struct usb_hcd *hcd)
 
         spin_lock_irqsave (&hcd_root_hub_lock, flags);
         if (hcd->rh_registered) {
+                hcd->poll_rh = 0;
+                del_timer(&hcd->rh_timer);
 
                 /* make khubd clean up old urbs and devices */
                 usb_set_device_state (hcd->self.root_hub,
@@ -1665,6 +1693,8 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
         hcd->self.bus_name = bus_name;
 
         init_timer(&hcd->rh_timer);
+        hcd->rh_timer.function = rh_timer_func;
+        hcd->rh_timer.data = (unsigned long) hcd;
 
         hcd->driver = driver;
         hcd->product_desc = (driver->product_desc) ? driver->product_desc :
@@ -1748,6 +1778,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
                 goto err3;
         }
 
+        if (hcd->uses_new_polling && hcd->poll_rh)
+                usb_hcd_poll_rh_status(hcd);
         return retval;
 
  err3:
@@ -1782,6 +1814,9 @@ void usb_remove_hcd(struct usb_hcd *hcd)
         spin_unlock_irq (&hcd_root_hub_lock);
         usb_disconnect(&hcd->self.root_hub);
 
+        hcd->poll_rh = 0;
+        del_timer_sync(&hcd->rh_timer);
+
         hcd->driver->stop(hcd);
         hcd->state = HC_STATE_HALT;
 
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 325a51656c3f..ac5752778e39 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -65,7 +65,8 @@ struct usb_hcd {	/* usb_bus.hcpriv points to this */
         const char              *product_desc;  /* product/vendor string */
         char                    irq_descr[24];  /* driver + bus # */
 
-        struct timer_list       rh_timer;       /* drives root hub */
+        struct timer_list       rh_timer;       /* drives root-hub polling */
+        struct urb              *status_urb;    /* the current status urb */
 
         /*
          * hardware info/state
@@ -76,6 +77,12 @@ struct usb_hcd {	/* usb_bus.hcpriv points to this */
         unsigned                remote_wakeup:1;/* sw should use wakeup? */
         unsigned                rh_registered:1;/* is root hub registered? */
 
+        /* The next flag is a stopgap, to be removed when all the HCDs
+         * support the new root-hub polling mechanism. */
+        unsigned                uses_new_polling:1;
+        unsigned                poll_rh:1;      /* poll for rh status? */
+        unsigned                poll_pending:1; /* status has changed? */
+
         int                     irq;            /* irq allocated */
         void __iomem            *regs;          /* device memory/io */
         u64                     rsrc_start;     /* memory/io resource start */
@@ -207,6 +214,8 @@ struct hc_driver {
         int             (*hub_suspend)(struct usb_hcd *);
         int             (*hub_resume)(struct usb_hcd *);
         int             (*start_port_reset)(struct usb_hcd *, unsigned port_num);
+        void            (*hub_irq_enable)(struct usb_hcd *);
+                /* Needed only if port-change IRQs are level-triggered */
 };
 
 extern void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb, struct pt_regs *regs);
@@ -243,7 +252,9 @@ void hcd_buffer_free (struct usb_bus *bus, size_t size,
 
 /* generic bus glue, needed for host controllers that don't use PCI */
 extern irqreturn_t usb_hcd_irq (int irq, void *__hcd, struct pt_regs *r);
+
 extern void usb_hc_died (struct usb_hcd *hcd);
+extern void usb_hcd_poll_rh_status(struct usb_hcd *hcd);
 
 /* -------------------------------------------------------------------------- */
 
@@ -360,6 +371,8 @@ extern wait_queue_head_t usb_kill_urb_queue;
 extern struct usb_bus *usb_bus_get (struct usb_bus *bus);
 extern void usb_bus_put (struct usb_bus *bus);
 
+extern void usb_enable_root_hub_irq (struct usb_bus *bus);
+
 extern int usb_find_interface_driver (struct usb_device *dev,
         struct usb_interface *interface);
 
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a8d879a85d04..6d1a330d577b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2787,6 +2787,11 @@ static void hub_events(void)
 
                 hub->activating = 0;
 
+                /* If this is a root hub, tell the HCD it's okay to
+                 * re-enable port-change interrupts now. */
+                if (!hdev->parent)
+                        usb_enable_root_hub_irq(hdev->bus);
+
 loop:
                 usb_unlock_device(hdev);
                 usb_put_intf(intf);