USB: Set usb_hcd->state and flags for shared roothubs.

The hcd->flags are in a sorry state.  Some of them are clearly specific to
the particular roothub (HCD_POLL_RH, HCD_POLL_PENDING, and
HCD_WAKEUP_PENDING), but some flags are related to PCI device state
(HCD_HW_ACCESSIBLE and HCD_SAW_IRQ).  This is an issue when one PCI device
can have two roothubs that share the same IRQ line and hardware.

Make sure to set HCD_FLAG_SAW_IRQ for both roothubs when an interrupt is
serviced, or an URB is unlinked without an interrupt.  (We can't tell if
the host actually serviced an interrupt for a particular bus, but we can
tell it serviced some interrupt.)

HCD_HW_ACCESSIBLE is set once by usb_add_hcd(), which is set for both
roothubs as they are added, so it doesn't need to be modified.
HCD_POLL_RH and HCD_POLL_PENDING are only checked by the USB core, and
they are never set by the xHCI driver, since the roothub never needs to be
polled.

The usb_hcd's state field is a similar mess.  Sometimes the state applies
to the underlying hardware: HC_STATE_HALT, HC_STATE_RUNNING, and
HC_STATE_QUIESCING.  But sometimes the state refers to the roothub state:
HC_STATE_RESUMING and HC_STATE_SUSPENDED.

Alan Stern recently made the USB core not rely on the hcd->state variable.
Internally, the xHCI driver still checks for HC_STATE_SUSPENDED, so leave
that code in.  Remove all references to HC_STATE_HALT, since the xHCI
driver only sets and doesn't test those variables.  We still have to set
HC_STATE_RUNNING, since Alan's patch has a bug that means the roothub
won't get registered if we don't set that.

Alan's patch made the USB core check a different variable when trying to
determine whether to suspend a roothub.  The xHCI host has a split
roothub, where two buses are registered for one PCI device.  Each bus in
the xHCI split roothub can be suspended separately, but both buses must be
suspended before the PCI device can be suspended.  Therefore, make sure
that the USB core checks HCD_RH_RUNNING() for both roothubs before
suspending the PCI host.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

3 files changed, 29 insertions, 4 deletions

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 88d9109..b992a88 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -367,6 +367,13 @@ static int check_root_hub_suspended(struct device *dev)
 		dev_warn(dev, "Root hub is not suspended\n");
 		return -EBUSY;
 	}
+	if (hcd->shared_hcd) {
+		hcd = hcd->shared_hcd;
+		if (HCD_RH_RUNNING(hcd)) {
+			dev_warn(dev, "Secondary root hub is not suspended\n");
+			return -EBUSY;
+		}
+	}
 	return 0;
 }
 
@@ -391,11 +398,16 @@ static int suspend_common(struct device *dev, bool do_wakeup)
 		 */
 		if (do_wakeup && HCD_WAKEUP_PENDING(hcd))
 			return -EBUSY;
+		if (do_wakeup && hcd->shared_hcd &&
+				HCD_WAKEUP_PENDING(hcd->shared_hcd))
+			return -EBUSY;
 		retval = hcd->driver->pci_suspend(hcd, do_wakeup);
 		suspend_report_result(hcd->driver->pci_suspend, retval);
 
 		/* Check again in case wakeup raced with pci_suspend */
-		if (retval == 0 && do_wakeup && HCD_WAKEUP_PENDING(hcd)) {
+		if ((retval == 0 && do_wakeup && HCD_WAKEUP_PENDING(hcd)) ||
+				(retval == 0 && do_wakeup && hcd->shared_hcd &&
+				 HCD_WAKEUP_PENDING(hcd->shared_hcd))) {
 			if (hcd->driver->pci_resume)
 				hcd->driver->pci_resume(hcd, false);
 			retval = -EBUSY;
@@ -426,7 +438,9 @@ static int resume_common(struct device *dev, int event)
 	struct usb_hcd		*hcd = pci_get_drvdata(pci_dev);
 	int			retval;
 
-	if (HCD_RH_RUNNING(hcd)) {
+	if (HCD_RH_RUNNING(hcd) ||
+			(hcd->shared_hcd &&
+			 HCD_RH_RUNNING(hcd->shared_hcd))) {
 		dev_dbg(dev, "can't resume, not suspended!\n");
 		return 0;
 	}
@@ -440,6 +454,8 @@ static int resume_common(struct device *dev, int event)
 	pci_set_master(pci_dev);
 
 	clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+	if (hcd->shared_hcd)
+		clear_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
 
 	if (hcd->driver->pci_resume && !HCD_DEAD(hcd)) {
 		if (event != PM_EVENT_AUTO_RESUME)
@@ -449,6 +465,8 @@ static int resume_common(struct device *dev, int event)
 				event == PM_EVENT_RESTORE);
 		if (retval) {
 			dev_err(dev, "PCI post-resume error %d!\n", retval);
+			if (hcd->shared_hcd)
+				usb_hc_died(hcd->shared_hcd);
 			usb_hc_died(hcd);
 		}
 	}
@@ -474,8 +492,9 @@ static int hcd_pci_suspend_noirq(struct device *dev)
 
 	pci_save_state(pci_dev);
 
-	/* If the root hub is dead rather than suspended,
-	 * disallow remote wakeup.
+	/* If the root hub is dead rather than suspended, disallow remote
+	 * wakeup.  usb_hc_died() should ensure that both hosts are marked as
+	 * dying, so we only need to check the primary roothub.
 	 */
 	if (HCD_DEAD(hcd))
 		device_set_wakeup_enable(dev, 0);
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index ba15eea..02b4dbf 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1153,6 +1153,8 @@ int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
 		dev_warn(hcd->self.controller, "Unlink after no-IRQ?  "
 			"Controller is probably using the wrong IRQ.\n");
 		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+		if (hcd->shared_hcd)
+			set_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
 	}
 
 	return 0;
@@ -2124,6 +2126,8 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
 		rc = IRQ_NONE;
 	} else {
 		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+		if (hcd->shared_hcd)
+			set_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
 
 		if (unlikely(hcd->state == HC_STATE_HALT))
 			usb_hc_died(hcd);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9e2b26c..47763be 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2181,6 +2181,8 @@ irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd)
 	irqreturn_t ret;
 
 	set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+	if (hcd->shared_hcd)
+		set_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
 
 	ret = xhci_irq(hcd);