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Commit 07d29b63 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: EHCI: add separate IAA watchdog timer 



This patch (as1028) was mostly written by David Brownell; I made only
a few changes (extra log info and a small bug fix -- which might
account for why David's version had to be reverted).  It adds a new
watchdog timer to the ehci-hcd driver to be used exclusively for
detecting lost or missing IAA notifications.

Previously a shared timer had been used, which may have led to some
problems as reported by Christian Hoffmann.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 2e2eb83f

drivers/usb/host/ehci-dbg.c

+1 −3
Original line number Diff line number Diff line
@@ -786,9 +786,7 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf) 
	}



	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;

	}

drivers/usb/host/ehci-hcd.c

+55 −22
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ static const char hcd_name [] = "ehci_hcd"; 
#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 */
@@ -267,6 +267,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci) 


/*-------------------------------------------------------------------------*/



static void end_unlink_async(struct ehci_hcd *ehci);

static void ehci_work(struct ehci_hcd *ehci);



#include "ehci-hub.c"
@@ -276,24 +277,40 @@ static void ehci_work(struct ehci_hcd *ehci); 


/*-------------------------------------------------------------------------*/



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;

	u32			status, cmd;



	spin_lock_irqsave (&ehci->lock, flags);

	WARN_ON(!ehci->reclaim);



	status = ehci_readl(ehci, &ehci->regs->status);

	cmd = ehci_readl(ehci, &ehci->regs->command);

	ehci_dbg(ehci, "IAA watchdog: status %x cmd %x\n", status, cmd);



	/* lost IAA irqs wedge things badly; seen with a vt8235 */

	/* lost IAA irqs wedge things badly; seen first with a vt8235 */

	if (ehci->reclaim) {

		u32		status = ehci_readl(ehci, &ehci->regs->status);

		if (status & STS_IAA) {

			ehci_vdbg (ehci, "lost IAA\n");

			COUNT (ehci->stats.lost_iaa);

			ehci_writel(ehci, STS_IAA, &ehci->regs->status);

			ehci->reclaim_ready = 1;

		}

		ehci_writel(ehci, cmd & ~CMD_IAAD, &ehci->regs->command);

		end_unlink_async(ehci);

	}



	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);
@@ -364,8 +381,6 @@ static void ehci_port_power (struct ehci_hcd *ehci, int is_on) 
static void ehci_work (struct ehci_hcd *ehci)

{

	timer_action_done (ehci, TIMER_IO_WATCHDOG);

	if (ehci->reclaim_ready)

		end_unlink_async (ehci);



	/* another CPU may drop ehci->lock during a schedule scan while

	 * it reports urb completions.  this flag guards against bogus
@@ -400,6 +415,7 @@ static void ehci_stop (struct usb_hcd *hcd) 


	/* no more interrupts ... */

	del_timer_sync (&ehci->watchdog);

	del_timer_sync(&ehci->iaa_watchdog);



	spin_lock_irq(&ehci->lock);

	if (HC_IS_RUNNING (hcd->state))
@@ -448,6 +464,10 @@ static int ehci_init(struct usb_hcd *hcd) 
	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;



	/*

	 * hw default: 1K periodic list heads, one per frame.

	 * periodic_size can shrink by USBCMD update if hcc_params allows.
@@ -464,7 +484,6 @@ static int ehci_init(struct usb_hcd *hcd) 
		ehci->i_thresh = 2 + HCC_ISOC_THRES(hcc_params);



	ehci->reclaim = NULL;

	ehci->reclaim_ready = 0;

	ehci->next_uframe = -1;



	/*
@@ -655,8 +674,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) 
	/* complete the unlinking of some qh [4.15.2.3] */

	if (status & STS_IAA) {

		COUNT (ehci->stats.reclaim);

		ehci->reclaim_ready = 1;

		bh = 1;

		end_unlink_async(ehci);

	}



	/* remote wakeup [4.3.1] */
@@ -762,10 +780,16 @@ static int ehci_urb_enqueue ( 


static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)

{

	/* if we need to use IAA and it's busy, defer */

	if (qh->qh_state == QH_STATE_LINKED

			&& ehci->reclaim

			&& HC_IS_RUNNING (ehci_to_hcd(ehci)->state)) {

	/* failfast */

	if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))

		end_unlink_async(ehci);



	/* if it's not linked then there's nothing to do */

	if (qh->qh_state != QH_STATE_LINKED)

		;



	/* defer till later if busy */

	else if (ehci->reclaim) {

		struct ehci_qh		*last;



		for (last = ehci->reclaim;
@@ -775,12 +799,8 @@ static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) 
		qh->qh_state = QH_STATE_UNLINK_WAIT;

		last->reclaim = qh;



	/* bypass IAA if the hc can't care */

	} else if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state) && ehci->reclaim)

		end_unlink_async (ehci);



	/* something else might have unlinked the qh by now */

	if (qh->qh_state == QH_STATE_LINKED)

	/* start IAA cycle */

	} else

		start_unlink_async (ehci, qh);

}
@@ -807,8 +827,20 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) 
		qh = (struct ehci_qh *) urb->hcpriv;

		if (!qh)

			break;

		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:

		qh = (struct ehci_qh *) urb->hcpriv;
@@ -899,6 +931,7 @@ ehci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep) 
		unlink_async (ehci, qh);

		/* FALL THROUGH */

	case QH_STATE_UNLINK:		/* wait for hw to finish? */

	case QH_STATE_UNLINK_WAIT:

idle_timeout:

		spin_unlock_irqrestore (&ehci->lock, flags);

		schedule_timeout_uninterruptible(1);

drivers/usb/host/ehci-hub.c

+1 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) 
	}

	ehci->command = ehci_readl(ehci, &ehci->regs->command);

	if (ehci->reclaim)

		ehci->reclaim_ready = 1;

		end_unlink_async(ehci);

	ehci_work(ehci);



	/* Unlike other USB host controller types, EHCI doesn't have

drivers/usb/host/ehci-pci.c

+1 −1
Original line number Diff line number Diff line
@@ -305,7 +305,7 @@ static int ehci_pci_resume(struct usb_hcd *hcd) 
	/* emptying the schedule aborts any urbs */

	spin_lock_irq(&ehci->lock);

	if (ehci->reclaim)

		ehci->reclaim_ready = 1;

		end_unlink_async(ehci);

	ehci_work(ehci);

	spin_unlock_irq(&ehci->lock);

drivers/usb/host/ehci-q.c

+2 −4
Original line number Diff line number Diff line
@@ -973,7 +973,7 @@ static void end_unlink_async (struct ehci_hcd *ehci) 
	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_hc32(qh->qh_dma);

	qh->qh_state = QH_STATE_IDLE;
@@ -983,7 +983,6 @@ static void end_unlink_async (struct ehci_hcd *ehci) 
	/* 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);
@@ -1059,11 +1058,10 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) 
		return;

	}



	ehci->reclaim_ready = 0;

	cmd |= CMD_IAAD;

	ehci_writel(ehci, cmd, &ehci->regs->command);

	(void)ehci_readl(ehci, &ehci->regs->command);

	timer_action (ehci, TIMER_IAA_WATCHDOG);

	iaa_watchdog_start(ehci);

}



/*-------------------------------------------------------------------------*/