Attachment 297411 Details for Bug 435787 – backported patch to fix it

[patch] backported patch to fix it

SBX00_USB_hang_fix_RHEL4.7.patch (text/plain), 10.15 KB, created by Shane Huang on 2008-03-10 10:20:21 UTC

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Creator: Shane Huang

Created: 2008-03-10 10:20:21 UTC

Size: 10.15 KB

patch

obsolete

>diff -ruN a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
>--- a/drivers/usb/host/ehci-dbg.c	2008-03-10 08:08:11.000000000 +0800
>+++ b/drivers/usb/host/ehci-dbg.c	2008-03-10 08:09:42.000000000 +0800
>@@ -704,9 +704,7 @@
> 	}
> 
> 	if (ehci->reclaim) {
>-		temp = scnprintf (next, size, "reclaim qh %p%s\n",
>-				ehci->reclaim,
>-				ehci->reclaim_ready ? " ready" : "");
>+		temp = scnprintf(next, size, "reclaim qh %p\n", ehci->reclaim);
> 		size -= temp;
> 		next += temp;
> 	}
>diff -ruN a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
>--- a/drivers/usb/host/ehci.h	2008-03-10 08:08:11.000000000 +0800
>+++ b/drivers/usb/host/ehci.h	2008-03-10 08:09:48.000000000 +0800
>@@ -52,7 +52,6 @@
> 	/* async schedule support */
> 	struct ehci_qh		*async;
> 	struct ehci_qh		*reclaim;
>-	unsigned		reclaim_ready : 1;
> 	unsigned		scanning : 1;
> 
> 	/* periodic schedule support */
>@@ -81,6 +80,7 @@
> 	struct dma_pool		*itd_pool;	/* itd per iso urb */
> 	struct dma_pool		*sitd_pool;	/* sitd per split iso urb */
> 
>+	struct timer_list       iaa_watchdog;
> 	struct timer_list	watchdog;
> 	struct notifier_block	reboot_notifier;
> 	unsigned long		actions;
>@@ -103,9 +103,21 @@
> #define hcd_to_ehci(hcd_ptr) container_of(hcd_ptr, struct ehci_hcd, hcd)
> 
> 
>+static inline void
>+iaa_watchdog_start(struct ehci_hcd *ehci)
>+{
>+	WARN_ON(timer_pending(&ehci->iaa_watchdog));
>+	mod_timer(&ehci->iaa_watchdog,
>+			jiffies + msecs_to_jiffies(EHCI_IAA_MSECS));
>+}
>+
>+static inline void iaa_watchdog_done(struct ehci_hcd *ehci)
>+{
>+	del_timer(&ehci->iaa_watchdog);
>+}
>+
> enum ehci_timer_action {
> 	TIMER_IO_WATCHDOG,
>-	TIMER_IAA_WATCHDOG,
> 	TIMER_ASYNC_SHRINK,
> 	TIMER_ASYNC_OFF,
> };
>@@ -123,9 +135,6 @@
> 		unsigned long t;
> 
> 		switch (action) {
>-		case TIMER_IAA_WATCHDOG:
>-			t = EHCI_IAA_JIFFIES;
>-			break;
> 		case TIMER_IO_WATCHDOG:
> 			t = EHCI_IO_JIFFIES;
> 			break;
>@@ -142,8 +151,7 @@
> 		// async queue SHRINK often precedes IAA.  while it's ready
> 		// to go OFF neither can matter, and afterwards the IO
> 		// watchdog stops unless there's still periodic traffic.
>-		if (action != TIMER_IAA_WATCHDOG
>-				&& t > ehci->watchdog.expires
>+		if (time_before_eq(t, ehci->watchdog.expires)
> 				&& timer_pending (&ehci->watchdog))
> 			return;
> 		mod_timer (&ehci->watchdog, t);
>diff -ruN a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
>--- a/drivers/usb/host/ehci-hcd.c	2008-03-10 08:08:11.000000000 +0800
>+++ b/drivers/usb/host/ehci-hcd.c	2008-03-10 08:09:57.000000000 +0800
>@@ -119,7 +119,7 @@
> #define	EHCI_TUNE_MULT_TT	1
> #define	EHCI_TUNE_FLS		2	/* (small) 256 frame schedule */
> 
>-#define EHCI_IAA_JIFFIES	(HZ/100)	/* arbitrary; ~10 msec */
>+#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	(HZ/200)	/* async qh unlink delay */
>@@ -246,6 +246,7 @@
> 
> /*-------------------------------------------------------------------------*/
> 
>+static void end_unlink_async(struct ehci_hcd *ehci, struct pt_regs *regs);
> static void ehci_work(struct ehci_hcd *ehci, struct pt_regs *regs);
> 
> #include "ehci-hub.c"
>@@ -255,26 +256,62 @@
> 
> /*-------------------------------------------------------------------------*/
> 
>-static void ehci_watchdog (unsigned long param)
>+static void ehci_iaa_watchdog(unsigned long param)
> {
> 	struct ehci_hcd		*ehci = (struct ehci_hcd *) param;
> 	unsigned long		flags;
> 
> 	spin_lock_irqsave (&ehci->lock, flags);
> 
>-	/* lost IAA irqs wedge things badly; seen with a vt8235 */
>-	if (ehci->reclaim) {
>-		u32		status = readl (&ehci->regs->status);
>-
>-		if (status & STS_IAA) {
>-			ehci_vdbg (ehci, "lost IAA\n");
>+	/* Lost IAA irqs wedge things badly; seen first with a vt8235.
>+	 * So we need this watchdog, but must protect it against both
>+	 * (a) SMP races against real IAA firing and retriggering, and
>+	 * (b) clean HC shutdown, when IAA watchdog was pending.
>+	 */
>+	if (ehci->reclaim
>+			&& !timer_pending(&ehci->iaa_watchdog)
>+			&& HCD_IS_RUNNING(ehci->hcd.state)) {
>+		u32 cmd, status;
>+
>+		/* If we get here, IAA is *REALLY* late.  It's barely
>+		 * conceivable that the system is so busy that CMD_IAAD
>+		 * is still legitimately set, so let's be sure it's
>+		 * clear before we read STS_IAA.  (The HC should clear
>+		 * CMD_IAAD when it sets STS_IAA.)
>+		 */
>+		cmd = readl(&ehci->regs->command);
>+		if (cmd & CMD_IAAD)
>+			writel(cmd & ~CMD_IAAD,
>+					&ehci->regs->command);
>+
>+		/* If IAA is set here it either legitimately triggered
>+		 * before we cleared IAAD above (but _way_ late, so we'll
>+		 * still count it as lost) ... or a silicon erratum:
>+		 * - VIA seems to set IAA without triggering the IRQ;
>+		 * - IAAD potentially cleared without setting IAA.
>+		 */
>+		status = readl(&ehci->regs->status);
>+		if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
> 			COUNT (ehci->stats.lost_iaa);
> 			writel (STS_IAA, &ehci->regs->status);
>-			ehci->reclaim_ready = 1;
> 		}
>+
>+		ehci_vdbg(ehci, "IAA watchdog: status %x cmd %x\n",
>+				status, cmd);
>+		end_unlink_async(ehci, NULL);
> 	}
> 
>- 	/* stop async processing after it's idled a bit */
>+	spin_unlock_irqrestore(&ehci->lock, flags);
>+}
>+
>+static void ehci_watchdog(unsigned long param)
>+{
>+	struct ehci_hcd         *ehci = (struct ehci_hcd *) param;
>+	unsigned long           flags;
>+
>+	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);
> 
>@@ -412,6 +449,10 @@
> 	ehci->watchdog.function = ehci_watchdog;
> 	ehci->watchdog.data = (unsigned long) ehci;
> 
>+	init_timer(&ehci->iaa_watchdog);
>+	ehci->iaa_watchdog.function = ehci_iaa_watchdog;
>+	ehci->iaa_watchdog.data = (unsigned long) ehci;
>+
> #ifdef	CONFIG_PCI
> 	/*
> 	 * The mask of consistent DMA must be set before we dig into DMA pool.
>@@ -630,6 +671,7 @@
> 		return;
> 	}
> 	del_timer_sync (&ehci->watchdog);
>+	del_timer_sync(&ehci->iaa_watchdog);
> 
> 	/* Turn off port power on all root hub ports. */
> 	rh_ports = HCS_N_PORTS (ehci->hcs_params);
>@@ -733,8 +775,6 @@
> static void ehci_work (struct ehci_hcd *ehci, struct pt_regs *regs)
> {
> 	timer_action_done (ehci, TIMER_IO_WATCHDOG);
>-	if (ehci->reclaim_ready)
>-		end_unlink_async (ehci, regs);
> 
> 	/* another CPU may drop ehci->lock during a schedule scan while
> 	 * it reports urb completions.  this flag guards against bogus
>@@ -761,7 +801,7 @@
> static irqreturn_t ehci_irq (struct usb_hcd *hcd, struct pt_regs *regs)
> {
> 	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);
>-	u32			status;
>+	u32			status, cmd;
> 	int			bh;
> 
> 	spin_lock (&ehci->lock);
>@@ -782,7 +822,7 @@
> 
> 	/* clear (just) interrupts */
> 	writel (status, &ehci->regs->status);
>-	readl (&ehci->regs->command);	/* unblock posted write */
>+	cmd = readl(&ehci->regs->command);
> 	bh = 0;
> 
> #ifdef	EHCI_VERBOSE_DEBUG
>@@ -803,9 +843,17 @@
> 
> 	/* complete the unlinking of some qh [4.15.2.3] */
> 	if (status & STS_IAA) {
>-		COUNT (ehci->stats.reclaim);
>-		ehci->reclaim_ready = 1;
>-		bh = 1;
>+		/* guard against (alleged) silicon errata */
>+		if (cmd & CMD_IAAD) {
>+			writel(cmd & ~CMD_IAAD,
>+					&ehci->regs->command);
>+			ehci_dbg(ehci, "IAA with IAAD still set?\n");
>+		}
>+		if (ehci->reclaim) {
>+			COUNT(ehci->stats.reclaim);
>+			end_unlink_async(ehci, NULL);
>+		} else
>+			ehci_dbg(ehci, "IAA with nothing to reclaim?\n");
> 	}
> 
> 	/* remote wakeup [4.3.1] */
>@@ -917,27 +965,19 @@
> 		if (!qh)
> 			break;
> 
>-		/* if we need to use IAA and it's busy, defer */
>-		if (qh->qh_state == QH_STATE_LINKED
>-				&& ehci->reclaim
>-				&& HCD_IS_RUNNING (ehci->hcd.state)
>-				) {
>-			struct ehci_qh		*last;
>-
>-			for (last = ehci->reclaim;
>-					last->reclaim;
>-					last = last->reclaim)
>-				continue;
>-			qh->qh_state = QH_STATE_UNLINK_WAIT;
>-			last->reclaim = qh;
>-
>-		/* bypass IAA if the hc can't care */
>-		} else if (!HCD_IS_RUNNING (ehci->hcd.state) && ehci->reclaim)
>-			end_unlink_async (ehci, NULL);
>-
>-		/* something else might have unlinked the qh by now */
>-		if (qh->qh_state == QH_STATE_LINKED)
>-			start_unlink_async (ehci, qh);
>+		switch (qh->qh_state) {
>+		case QH_STATE_LINKED:
>+		case QH_STATE_COMPLETING:
>+			//unlink_async(ehci, qh);
>+			break;
>+		case QH_STATE_UNLINK:
>+		case QH_STATE_UNLINK_WAIT:
>+			/* already started */
>+			break;
>+		case QH_STATE_IDLE:
>+			WARN_ON(1);
>+			break;
>+		}
> 		break;
> 
> 	case PIPE_INTERRUPT:
>@@ -1017,6 +1057,7 @@
> 		qh->qh_state = QH_STATE_IDLE;
> 	switch (qh->qh_state) {
> 	case QH_STATE_UNLINK:		/* wait for hw to finish? */
>+	case QH_STATE_UNLINK_WAIT:
> idle_timeout:
> 		spin_unlock_irqrestore (&ehci->lock, flags);
> 		set_current_state (TASK_UNINTERRUPTIBLE);
>diff -ruN a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
>--- a/drivers/usb/host/ehci-hub.c	2008-03-10 08:08:11.000000000 +0800
>+++ b/drivers/usb/host/ehci-hub.c	2008-03-10 08:09:53.000000000 +0800
>@@ -41,6 +41,8 @@
> 		return 0;
> 	if (time_before (jiffies, ehci->next_statechange))
> 		return -EAGAIN;
>+	del_timer_sync(&ehci->watchdog);
>+	del_timer_sync(&ehci->iaa_watchdog);
> 
> 	port = HCS_N_PORTS (ehci->hcs_params);
> 	spin_lock_irq (&ehci->lock);
>@@ -71,7 +73,7 @@
> 	ehci->command = readl (&ehci->regs->command);
> 	writel (ehci->command & ~CMD_RUN, &ehci->regs->command);
> 	if (ehci->reclaim)
>-		ehci->reclaim_ready = 1;
>+		end_unlink_async(ehci, NULL);
> 	ehci_work(ehci, NULL);
> 	(void) handshake (&ehci->regs->status, STS_HALT, STS_HALT, 2000);
> 
>diff -ruN a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
>--- a/drivers/usb/host/ehci-q.c	2008-03-10 08:08:12.000000000 +0800
>+++ b/drivers/usb/host/ehci-q.c	2008-03-10 08:10:06.000000000 +0800
>@@ -938,7 +938,7 @@
> 	struct ehci_qh		*qh = ehci->reclaim;
> 	struct ehci_qh		*next;
> 
>-	timer_action_done (ehci, TIMER_IAA_WATCHDOG);
>+	iaa_watchdog_done(ehci);
> 
> 	// qh->hw_next = cpu_to_le32 (qh->qh_dma);
> 	qh->qh_state = QH_STATE_IDLE;
>@@ -948,7 +948,6 @@
> 	/* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
> 	next = qh->reclaim;
> 	ehci->reclaim = next;
>-	ehci->reclaim_ready = 0;
> 	qh->reclaim = NULL;
> 
> 	qh_completions (ehci, qh, regs);
>@@ -1024,11 +1023,10 @@
> 		return;
> 	}
> 
>-	ehci->reclaim_ready = 0;
> 	cmd |= CMD_IAAD;
> 	writel (cmd, &ehci->regs->command);
> 	(void) readl (&ehci->regs->command);
>-	timer_action (ehci, TIMER_IAA_WATCHDOG);
>+	iaa_watchdog_start(ehci);
> }
> 
> /*-------------------------------------------------------------------------*/

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Attachments on bug 435787: 297411 | 297591 | 301746 | 301913 | 303125 | 304091