6 files changed, 23 insertions, 18 deletions

diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
index 7612095..f0c00de 100644
--- a/drivers/usb/host/ehci-dbg.c
+++ b/drivers/usb/host/ehci-dbg.c
@@ -706,6 +706,8 @@ static const char *rh_state_string(struct ehci_hcd *ehci)
 		return "suspended";
 	case EHCI_RH_RUNNING:
 		return "running";
+	case EHCI_RH_STOPPING:
+		return "stopping";
 	}
 	return "?";
 }
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 8b75e42..bc94822 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -357,10 +357,8 @@ static void ehci_quiesce (struct ehci_hcd *ehci)
 {
 	u32	temp;
 
-#ifdef DEBUG
 	if (ehci->rh_state != EHCI_RH_RUNNING)
-		BUG ();
-#endif
+		return;
 
 	/* wait for any schedule enables/disables to take effect */
 	temp = (ehci->command << 10) & (STS_ASS | STS_PSS);
@@ -494,6 +492,7 @@ static void ehci_shutdown(struct usb_hcd *hcd)
 	del_timer_sync(&ehci->iaa_watchdog);
 
 	spin_lock_irq(&ehci->lock);
+	ehci->rh_state = EHCI_RH_STOPPING;
 	ehci_silence_controller(ehci);
 	spin_unlock_irq(&ehci->lock);
 }
@@ -562,8 +561,7 @@ static void ehci_stop (struct usb_hcd *hcd)
 	del_timer_sync(&ehci->iaa_watchdog);
 
 	spin_lock_irq(&ehci->lock);
-	if (ehci->rh_state == EHCI_RH_RUNNING)
-		ehci_quiesce (ehci);
+	ehci_quiesce(ehci);
 
 	ehci_silence_controller(ehci);
 	ehci_reset (ehci);
@@ -951,6 +949,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 	/* PCI errors [4.15.2.4] */
 	if (unlikely ((status & STS_FATAL) != 0)) {
 		ehci_err(ehci, "fatal error\n");
+		ehci->rh_state = EHCI_RH_STOPPING;
 		dbg_cmd(ehci, "fatal", cmd);
 		dbg_status(ehci, "fatal", status);
 		ehci_halt(ehci);
@@ -1026,7 +1025,7 @@ static int ehci_urb_enqueue (
 static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 {
 	/* failfast */
-	if (ehci->rh_state != EHCI_RH_RUNNING && ehci->async_unlink)
+	if (ehci->rh_state < EHCI_RH_RUNNING && ehci->async_unlink)
 		end_unlink_async(ehci);
 
 	/* If the QH isn't linked then there's nothing we can do
@@ -1148,7 +1147,7 @@ rescan:
 		goto idle_timeout;
 	}
 
-	if (ehci->rh_state != EHCI_RH_RUNNING)
+	if (ehci->rh_state < EHCI_RH_RUNNING)
 		qh->qh_state = QH_STATE_IDLE;
 	switch (qh->qh_state) {
 	case QH_STATE_LINKED:
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 77d3324..fb1b99e 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -227,8 +227,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
 	}
 
 	/* stop schedules, clean any completed work */
-	if (ehci->rh_state == EHCI_RH_RUNNING)
-		ehci_quiesce (ehci);
+	ehci_quiesce(ehci);
 	ehci_work(ehci);
 
 	/* Unlike other USB host controller types, EHCI doesn't have
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 5193612..285d5a0 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -433,7 +433,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 		/* stop scanning when we reach qtds the hc is using */
 		} else if (likely (!stopped
-				&& ehci->rh_state == EHCI_RH_RUNNING)) {
+				&& ehci->rh_state >= EHCI_RH_RUNNING)) {
 			break;
 
 		/* scan the whole queue for unlinks whenever it stops */
@@ -441,7 +441,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 			stopped = 1;
 
 			/* cancel everything if we halt, suspend, etc */
-			if (ehci->rh_state != EHCI_RH_RUNNING)
+			if (ehci->rh_state < EHCI_RH_RUNNING)
 				last_status = -ESHUTDOWN;
 
 			/* this qtd is active; skip it unless a previous qtd
@@ -1241,7 +1241,7 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	wmb ();
 
 	/* If the controller isn't running, we don't have to wait for it */
-	if (unlikely(ehci->rh_state != EHCI_RH_RUNNING)) {
+	if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
 		/* if (unlikely (qh->unlink_next != 0))
 		 *	this will recurse, probably not much
 		 */
@@ -1263,7 +1263,7 @@ static void scan_async (struct ehci_hcd *ehci)
 	enum ehci_timer_action	action = TIMER_IO_WATCHDOG;
 
 	timer_action_done (ehci, TIMER_ASYNC_SHRINK);
-	stopped = (ehci->rh_state != EHCI_RH_RUNNING);
+	stopped = (ehci->rh_state < EHCI_RH_RUNNING);
 
 	ehci->qh_scan_next = ehci->async->qh_next.qh;
 	while (ehci->qh_scan_next) {
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 027df3d..3429b8a3 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -2299,7 +2299,7 @@ scan_periodic (struct ehci_hcd *ehci)
 	 * Touches as few pages as possible:  cache-friendly.
 	 */
 	now_uframe = ehci->next_uframe;
-	if (ehci->rh_state == EHCI_RH_RUNNING) {
+	if (ehci->rh_state >= EHCI_RH_RUNNING) {
 		clock = ehci_read_frame_index(ehci);
 		clock_frame = (clock >> 3) & (ehci->periodic_size - 1);
 	} else  {
@@ -2334,7 +2334,7 @@ restart:
 			union ehci_shadow	temp;
 			int			live;
 
-			live = (ehci->rh_state == EHCI_RH_RUNNING);
+			live = (ehci->rh_state >= EHCI_RH_RUNNING);
 			switch (hc32_to_cpu(ehci, type)) {
 			case Q_TYPE_QH:
 				/* handle any completions */
@@ -2459,7 +2459,7 @@ restart:
 		 * We can't advance our scan without collecting the ISO
 		 * transfers that are still pending in this frame.
 		 */
-		if (incomplete && ehci->rh_state == EHCI_RH_RUNNING) {
+		if (incomplete && ehci->rh_state >= EHCI_RH_RUNNING) {
 			ehci->next_uframe = now_uframe;
 			break;
 		}
@@ -2475,7 +2475,7 @@ restart:
 		if (now_uframe == clock) {
 			unsigned	now;
 
-			if (ehci->rh_state != EHCI_RH_RUNNING
+			if (ehci->rh_state < EHCI_RH_RUNNING
 					|| ehci->periodic_sched == 0)
 				break;
 			ehci->next_uframe = now_uframe;
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 475f23e..9e8e82e 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -62,10 +62,15 @@ struct ehci_stats {
 
 #define	EHCI_MAX_ROOT_PORTS	15		/* see HCS_N_PORTS */
 
+/*
+ * ehci_rh_state values of EHCI_RH_RUNNING or above mean that the
+ * controller may be doing DMA.  Lower values mean there's no DMA.
+ */
 enum ehci_rh_state {
 	EHCI_RH_HALTED,
 	EHCI_RH_SUSPENDED,
-	EHCI_RH_RUNNING
+	EHCI_RH_RUNNING,
+	EHCI_RH_STOPPING
 };
 
 struct ehci_hcd {			/* one per controller */