---

yaml --- r: 364374 b: refs/heads/master c: 7bc782d h: refs/heads/master v: v3
git-mirror · Mar 25, 2013 · 7f6fd88 · 7f6fd88
1 parent 4d0687a
commit 7f6fd88
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Showing 5 changed files with 40 additions and 55 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 79bcf7b02ba3d45bafe81a2753cedb8ef49548e3
+refs/heads/master: 7bc782d73c7db042ecc965866b8c1c2b7d6e93d6
diff --git a/trunk/drivers/usb/host/ehci-hcd.c b/trunk/drivers/usb/host/ehci-hcd.c
@@ -903,11 +903,14 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 		qh = (struct ehci_qh *) urb->hcpriv;
 		if (!qh)
 			break;
+		qh->exception = 1;
 		switch (qh->qh_state) {
 		case QH_STATE_LINKED:
-		case QH_STATE_COMPLETING:
 			start_unlink_async(ehci, qh);
 			break;
+		case QH_STATE_COMPLETING:
+			qh->dequeue_during_giveback = 1;
+			break;
 		case QH_STATE_UNLINK:
 		case QH_STATE_UNLINK_WAIT:
 			/* already started */
@@ -923,11 +926,14 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 		qh = (struct ehci_qh *) urb->hcpriv;
 		if (!qh)
 			break;
+		qh->exception = 1;
 		switch (qh->qh_state) {
 		case QH_STATE_LINKED:
-		case QH_STATE_COMPLETING:
 			start_unlink_intr(ehci, qh);
 			break;
+		case QH_STATE_COMPLETING:
+			qh->dequeue_during_giveback = 1;
+			break;
 		case QH_STATE_IDLE:
 			qh_completions (ehci, qh);
 			break;
@@ -984,6 +990,7 @@ ehci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep)
 		goto done;
 	}
 
+	qh->exception = 1;
 	if (ehci->rh_state < EHCI_RH_RUNNING)
 		qh->qh_state = QH_STATE_IDLE;
 	switch (qh->qh_state) {
@@ -1052,13 +1059,12 @@ ehci_endpoint_reset(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
 		usb_settoggle(qh->dev, epnum, is_out, 0);
 		if (!list_empty(&qh->qtd_list)) {
 			WARN_ONCE(1, "clear_halt for a busy endpoint\n");
-		} else if (qh->qh_state == QH_STATE_LINKED ||
-				qh->qh_state == QH_STATE_COMPLETING) {
-
+		} else {
 			/* The toggle value in the QH can't be updated
 			 * while the QH is active.  Unlink it now;
 			 * re-linking will call qh_refresh().
 			 */
+			qh->exception = 1;
 			if (eptype == USB_ENDPOINT_XFER_BULK)
 				start_unlink_async(ehci, qh);
 			else

diff --git a/trunk/drivers/usb/host/ehci-q.c b/trunk/drivers/usb/host/ehci-q.c
@@ -322,7 +322,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
  rescan:
 	last = NULL;
 	last_status = -EINPROGRESS;
-	qh->needs_rescan = 0;
+	qh->dequeue_during_giveback = 0;
 
 	/* remove de-activated QTDs from front of queue.
 	 * after faults (including short reads), cleanup this urb
@@ -518,18 +518,12 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	}
 
 	/* Do we need to rescan for URBs dequeued during a giveback? */
-	if (unlikely(qh->needs_rescan)) {
+	if (unlikely(qh->dequeue_during_giveback)) {
 		/* If the QH is already unlinked, do the rescan now. */
 		if (state == QH_STATE_IDLE)
 			goto rescan;
 
-		/* Otherwise we have to wait until the QH is fully unlinked.
-		 * Our caller will start an unlink if qh->needs_rescan is
-		 * set.  But if an unlink has already started, nothing needs
-		 * to be done.
-		 */
-		if (state != QH_STATE_LINKED)
-			qh->needs_rescan = 0;
+		/* Otherwise the caller must unlink the QH. */
 	}
 
 	/* restore original state; caller must unlink or relink */
@@ -538,29 +532,23 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	/* be sure the hardware's done with the qh before refreshing
 	 * it after fault cleanup, or recovering from silicon wrongly
 	 * overlaying the dummy qtd (which reduces DMA chatter).
+	 *
+	 * We won't refresh a QH that's linked (after the HC
+	 * stopped the queue).  That avoids a race:
+	 *  - HC reads first part of QH;
+	 *  - CPU updates that first part and the token;
+	 *  - HC reads rest of that QH, including token
+	 * Result:  HC gets an inconsistent image, and then
+	 * DMAs to/from the wrong memory (corrupting it).
+	 *
+	 * That should be rare for interrupt transfers,
+	 * except maybe high bandwidth ...
 	 */
-	if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci)) {
-		if (state == QH_STATE_LINKED) {
-			/*
-			 * We won't refresh a QH that's linked (after the HC
-			 * stopped the queue).  That avoids a race:
-			 *  - HC reads first part of QH;
-			 *  - CPU updates that first part and the token;
-			 *  - HC reads rest of that QH, including token
-			 * Result:  HC gets an inconsistent image, and then
-			 * DMAs to/from the wrong memory (corrupting it).
-			 *
-			 * That should be rare for interrupt transfers,
-			 * except maybe high bandwidth ...
-			 *
-			 * Therefore tell the caller to start an unlink.
-			 */
-			qh->needs_rescan = 1;
-		}
-		/* otherwise, unlink already started */
-	}
+	if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci))
+		qh->exception = 1;
 
-	return qh->needs_rescan;
+	/* Let the caller know if the QH needs to be unlinked. */
+	return qh->exception;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -1002,8 +990,9 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	head->qh_next.qh = qh;
 	head->hw->hw_next = dma;
 
-	qh->xacterrs = 0;
 	qh->qh_state = QH_STATE_LINKED;
+	qh->xacterrs = 0;
+	qh->exception = 0;
 	/* qtd completions reported later by interrupt */
 
 	enable_async(ehci);
@@ -1317,16 +1306,9 @@ static void unlink_empty_async_suspended(struct ehci_hcd *ehci)
 
 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
 {
-	/*
-	 * If the QH isn't linked then there's nothing we can do
-	 * unless we were called during a giveback, in which case
-	 * qh_completions() has to deal with it.
-	 */
-	if (qh->qh_state != QH_STATE_LINKED) {
-		if (qh->qh_state == QH_STATE_COMPLETING)
-			qh->needs_rescan = 1;
+	/* If the QH isn't linked then there's nothing we can do. */
+	if (qh->qh_state != QH_STATE_LINKED)
 		return;
-	}
 
 	single_unlink_async(ehci, qh);
 	start_iaa_cycle(ehci, false);

diff --git a/trunk/drivers/usb/host/ehci-sched.c b/trunk/drivers/usb/host/ehci-sched.c
@@ -539,6 +539,7 @@ static void qh_link_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 	}
 	qh->qh_state = QH_STATE_LINKED;
 	qh->xacterrs = 0;
+	qh->exception = 0;
 
 	/* update per-qh bandwidth for usbfs */
 	ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->period
@@ -602,15 +603,9 @@ static void qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 {
-	/* If the QH isn't linked then there's nothing we can do
-	 * unless we were called during a giveback, in which case
-	 * qh_completions() has to deal with it.
-	 */
-	if (qh->qh_state != QH_STATE_LINKED) {
-		if (qh->qh_state == QH_STATE_COMPLETING)
-			qh->needs_rescan = 1;
+	/* If the QH isn't linked then there's nothing we can do. */
+	if (qh->qh_state != QH_STATE_LINKED)
 		return;
-	}
 
 	qh_unlink_periodic (ehci, qh);
 

diff --git a/trunk/drivers/usb/host/ehci.h b/trunk/drivers/usb/host/ehci.h
@@ -384,7 +384,6 @@ struct ehci_qh {
 
 	unsigned		unlink_cycle;
 
-	u8			needs_rescan;	/* Dequeue during giveback */
 	u8			qh_state;
 #define	QH_STATE_LINKED		1		/* HC sees this */
 #define	QH_STATE_UNLINK		2		/* HC may still see this */
@@ -407,6 +406,9 @@ struct ehci_qh {
 	struct usb_device	*dev;		/* access to TT */
 	unsigned		is_out:1;	/* bulk or intr OUT */
 	unsigned		clearing_tt:1;	/* Clear-TT-Buf in progress */
+	unsigned		dequeue_during_giveback:1;
+	unsigned		exception:1;	/* got a fault, or an unlink
+						   was requested */
 };
 
 /*-------------------------------------------------------------------------*/