---

yaml
---
r: 317024
b: refs/heads/master
c: 3144661
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9671cd7a91059bcd27665a884ee6568d31ef6857
+refs/heads/master: 314466101c6ae14f6f5db8a86eda1509ba2c02a8

trunk/drivers/usb/host/ehci-hcd.c

@@ -95,7 +95,6 @@ static const char	hcd_name [] = "ehci_hcd";
 
 #define EHCI_IAA_MSECS		10		/* arbitrary */
 #define EHCI_IO_JIFFIES		(HZ/10)		/* io watchdog > irq_thresh */
-#define EHCI_ASYNC_JIFFIES	(HZ/20)		/* async idle timeout */
 #define EHCI_SHRINK_JIFFIES	(DIV_ROUND_UP(HZ, 200) + 1)
 						/* 5-ms async qh unlink delay */
 
@@ -137,7 +136,7 @@ timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
 	 * SHRINK were pending, OFF would never be requested.
 	 */
 	if (timer_pending(&ehci->watchdog)
-			&& ((BIT(TIMER_ASYNC_SHRINK) | BIT(TIMER_ASYNC_OFF))
+			&& (BIT(TIMER_ASYNC_SHRINK)
 				& ehci->actions))
 		return;
 
@@ -150,9 +149,6 @@ timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
 				return;
 			t = EHCI_IO_JIFFIES;
 			break;
-		case TIMER_ASYNC_OFF:
-			t = EHCI_ASYNC_JIFFIES;
-			break;
 		/* case TIMER_ASYNC_SHRINK: */
 		default:
 			t = EHCI_SHRINK_JIFFIES;
@@ -376,10 +372,6 @@ static void ehci_watchdog(unsigned long param)
 
 	spin_lock_irqsave(&ehci->lock, flags);
 
-	/* stop async processing after it's idled a bit */
-	if (test_bit (TIMER_ASYNC_OFF, &ehci->actions))
-		start_unlink_async (ehci, ehci->async);
-
 	/* ehci could run by timer, without IRQs ... */
 	ehci_work (ehci);
 
@@ -470,7 +462,8 @@ static void ehci_work (struct ehci_hcd *ehci)
 	if (ehci->scanning)
 		return;
 	ehci->scanning = 1;
-	scan_async (ehci);
+	if (ehci->async_count)
+		scan_async(ehci);
 	if (ehci->next_uframe != -1)
 		scan_periodic (ehci);
 	ehci->scanning = 0;

trunk/drivers/usb/host/ehci-q.c

@@ -964,6 +964,30 @@ qh_make (
 
 /*-------------------------------------------------------------------------*/
 
+static void enable_async(struct ehci_hcd *ehci)
+{
+	if (ehci->async_count++)
+		return;
+
+	/* Stop waiting to turn off the async schedule */
+	ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_ASYNC);
+
+	/* Don't start the schedule until ASS is 0 */
+	ehci_poll_ASS(ehci);
+}
+
+static void disable_async(struct ehci_hcd *ehci)
+{
+	if (--ehci->async_count)
+		return;
+
+	/* The async schedule and async_unlink list are supposed to be empty */
+	WARN_ON(ehci->async->qh_next.qh || ehci->async_unlink);
+
+	/* Don't turn off the schedule until ASS is 1 */
+	ehci_poll_ASS(ehci);
+}
+
 /* move qh (and its qtds) onto async queue; maybe enable queue.  */
 
 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
@@ -977,24 +1001,11 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 	WARN_ON(qh->qh_state != QH_STATE_IDLE);
 
-	/* (re)start the async schedule? */
-	head = ehci->async;
-	timer_action_done (ehci, TIMER_ASYNC_OFF);
-	if (!head->qh_next.qh) {
-		if (!(ehci->command & CMD_ASE)) {
-			/* in case a clear of CMD_ASE didn't take yet */
-			(void)handshake(ehci, &ehci->regs->status,
-					STS_ASS, 0, 150);
-			ehci->command |= CMD_ASE;
-			ehci_writel(ehci, ehci->command, &ehci->regs->command);
-			/* posted write need not be known to HC yet ... */
-		}
-	}
-
 	/* clear halt and/or toggle; and maybe recover from silicon quirk */
 	qh_refresh(ehci, qh);
 
 	/* splice right after start */
+	head = ehci->async;
 	qh->qh_next = head->qh_next;
 	qh->hw->hw_next = head->hw->hw_next;
 	wmb ();
@@ -1005,6 +1016,8 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	qh->xacterrs = 0;
 	qh->qh_state = QH_STATE_LINKED;
 	/* qtd completions reported later by interrupt */
+
+	enable_async(ehci);
 }
 
 /*-------------------------------------------------------------------------*/
@@ -1173,16 +1186,10 @@ static void end_unlink_async (struct ehci_hcd *ehci)
 
 	qh_completions (ehci, qh);
 
-	if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
+	if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING)
 		qh_link_async (ehci, qh);
-	} else {
-		/* it's not free to turn the async schedule on/off; leave it
-		 * active but idle for a while once it empties.
-		 */
-		if (ehci->rh_state == EHCI_RH_RUNNING
-				&& ehci->async->qh_next.qh == NULL)
-			timer_action (ehci, TIMER_ASYNC_OFF);
-	}
+
+	disable_async(ehci);
 
 	if (next) {
 		ehci->async_unlink = NULL;
@@ -1210,21 +1217,6 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 		BUG ();
 #endif
 
-	/* stop async schedule right now? */
-	if (unlikely (qh == ehci->async)) {
-		/* can't get here without STS_ASS set */
-		if (ehci->rh_state != EHCI_RH_HALTED
-				&& !ehci->async_unlink) {
-			/* ... and CMD_IAAD clear */
-			ehci->command &= ~CMD_ASE;
-			ehci_writel(ehci, ehci->command, &ehci->regs->command);
-			wmb ();
-			// handshake later, if we need to
-			timer_action_done (ehci, TIMER_ASYNC_OFF);
-		}
-		return;
-	}
-
 	qh->qh_state = QH_STATE_UNLINK;
 	ehci->async_unlink = qh;
 	if (!qh->unlink_next)

trunk/drivers/usb/host/ehci-timer.c

@@ -67,8 +67,10 @@ static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
  * the event types indexed by enum ehci_hrtimer_event in ehci.h.
  */
 static unsigned event_delays_ns[] = {
+	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_ASS */
 	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_PSS */
 	10 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_PERIODIC */
+	15 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_ASYNC */
 };
 
 /* Enable a pending hrtimer event */
@@ -91,6 +93,51 @@ static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
 }
 
 
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void ehci_poll_ASS(struct ehci_hcd *ehci)
+{
+	unsigned	actual, want;
+
+	/* Don't enable anything if the controller isn't running (e.g., died) */
+	if (ehci->rh_state != EHCI_RH_RUNNING)
+		return;
+
+	want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
+	actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 20 ms */
+		if (ehci->ASS_poll_count++ < 20) {
+			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
+			return;
+		}
+		ehci_warn(ehci, "Waited too long for the async schedule status, giving up\n");
+	}
+	ehci->ASS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (ehci->async_count > 0)
+			ehci_set_command_bit(ehci, CMD_ASE);
+
+	} else {		/* Running */
+		if (ehci->async_count == 0) {
+
+			/* Turn off the schedule after a while */
+			ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_ASYNC,
+					true);
+		}
+	}
+}
+
+/* Turn off the async schedule after a brief delay */
+static void ehci_disable_ASE(struct ehci_hcd *ehci)
+{
+	ehci_clear_command_bit(ehci, CMD_ASE);
+}
+
+
 /* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
 static void ehci_poll_PSS(struct ehci_hcd *ehci)
 {
@@ -151,8 +198,10 @@ static void ehci_disable_PSE(struct ehci_hcd *ehci)
  * enum ehci_hrtimer_event in ehci.h.
  */
 static void (*event_handlers[])(struct ehci_hcd *) = {
+	ehci_poll_ASS,			/* EHCI_HRTIMER_POLL_ASS */
 	ehci_poll_PSS,			/* EHCI_HRTIMER_POLL_PSS */
 	ehci_disable_PSE,		/* EHCI_HRTIMER_DISABLE_PERIODIC */
+	ehci_disable_ASE,		/* EHCI_HRTIMER_DISABLE_ASYNC */
 };
 
 static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)

trunk/drivers/usb/host/ehci.h

@@ -79,8 +79,10 @@ enum ehci_rh_state {
  * ehci-timer.c) in parallel with this list.
  */
 enum ehci_hrtimer_event {
+	EHCI_HRTIMER_POLL_ASS,		/* Poll for async schedule off */
 	EHCI_HRTIMER_POLL_PSS,		/* Poll for periodic schedule off */
 	EHCI_HRTIMER_DISABLE_PERIODIC,	/* Wait to disable periodic sched */
+	EHCI_HRTIMER_DISABLE_ASYNC,	/* Wait to disable async sched */
 	EHCI_HRTIMER_NUM_EVENTS		/* Must come last */
 };
 #define EHCI_HRTIMER_NO_EVENT	99
@@ -93,6 +95,7 @@ struct ehci_hcd {			/* one per controller */
 	struct hrtimer		hrtimer;
 
 	int			PSS_poll_count;
+	int			ASS_poll_count;
 
 	/* glue to PCI and HCD framework */
 	struct ehci_caps __iomem *caps;
@@ -110,6 +113,7 @@ struct ehci_hcd {			/* one per controller */
 	struct ehci_qh		*async_unlink_last;
 	struct ehci_qh		*qh_scan_next;
 	unsigned		scanning : 1;
+	unsigned		async_count;	/* async activity count */
 
 	/* periodic schedule support */
 #define	DEFAULT_I_TDPS		1024		/* some HCs can do less */
@@ -229,7 +233,6 @@ static inline void iaa_watchdog_done(struct ehci_hcd *ehci)
 enum ehci_timer_action {
 	TIMER_IO_WATCHDOG,
 	TIMER_ASYNC_SHRINK,
-	TIMER_ASYNC_OFF,
 };
 
 static inline void