[PATCH] USB: Don't resume root hub if the controller is suspended

Root hubs can't be resumed if their parent controller device is still
suspended.  This patch (as925) adds a check for that condition in
hcd_bus_resume() and prevents it from being treated as a fatal
controller failure.

ehci-hcd is updated to add the corresponding test.  Unnecessary
debugging messages are removed from uhci-hcd and dummy-hcd.  The
error return code from dummy-hcd is changed to -ESHUTDOWN, the same as
the others.  ohci-hcd doesn't need any changes.

Suspend handling in the non-PCI host drivers is somewhat hit-and-miss.
This patch shouldn't have any effect on them.

Signed-off-by: Alan Stern <[email protected]>

---

This particular failure scenario is unlikely to occur; about the only 
thing that could cause it would be the ksuspend_usb thread trying to do 
something while it was supposed to be frozen.

Still, I think it's good to make the drivers detect the error and
return consistent codes... just in case.


Index: usb-2.6/drivers/usb/core/hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/hcd.c
+++ usb-2.6/drivers/usb/core/hcd.c
@@ -1276,6 +1276,7 @@ int hcd_bus_resume(struct usb_device *rh
 {
 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
 	int		status;
+	int		old_state = hcd->state;
 
 	dev_dbg(&rhdev->dev, "usb %s%s\n",
 			rhdev->auto_pm ? "auto-" : "", "resume");
@@ -1294,9 +1295,11 @@ int hcd_bus_resume(struct usb_device *rh
 				: USB_STATE_ADDRESS);
 		hcd->state = HC_STATE_RUNNING;
 	} else {
+		hcd->state = old_state;
 		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
 				"resume", status);
-		usb_hc_died(hcd);
+		if (status != -ESHUTDOWN)
+			usb_hc_died(hcd);
 	}
 	return status;
 }
Index: usb-2.6/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hub.c
+++ usb-2.6/drivers/usb/host/ehci-hub.c
@@ -199,6 +199,10 @@ static int ehci_bus_resume (struct usb_h
 	if (time_before (jiffies, ehci->next_statechange))
 		msleep(5);
 	spin_lock_irq (&ehci->lock);
+	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+		spin_unlock_irq(&ehci->lock);
+		return -ESHUTDOWN;
+	}
 
 	/* Ideally and we've got a real resume here, and no port's power
 	 * was lost.  (For PCI, that means Vaux was maintained.)  But we
Index: usb-2.6/drivers/usb/host/uhci-hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/uhci-hcd.c
+++ usb-2.6/drivers/usb/host/uhci-hcd.c
@@ -730,10 +730,9 @@ static int uhci_rh_resume(struct usb_hcd
 	int rc = 0;
 
 	spin_lock_irq(&uhci->lock);
-	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
-		dev_warn(&hcd->self.root_hub->dev, "HC isn't running!\n");
+	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
 		rc = -ESHUTDOWN;
-	} else if (!uhci->dead)
+	else if (!uhci->dead)
 		wakeup_rh(uhci);
 	spin_unlock_irq(&uhci->lock);
 	return rc;
Index: usb-2.6/drivers/usb/gadget/dummy_hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/gadget/dummy_hcd.c
+++ usb-2.6/drivers/usb/gadget/dummy_hcd.c
@@ -1784,8 +1784,7 @@ static int dummy_bus_resume (struct usb_
 
 	spin_lock_irq (&dum->lock);
 	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
-		dev_warn (&hcd->self.root_hub->dev, "HC isn't running!\n");
-		rc = -ENODEV;
+		rc = -ESHUTDOWN;
 	} else {
 		dum->rh_state = DUMMY_RH_RUNNING;
 		set_link_state (dum);


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