[linux-2.6-block.git] / drivers / usb / host / ehci-timer.c

/*
 * Copyright (C) 2012 by Alan Stern
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

/* This file is part of ehci-hcd.c */

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

/* Set a bit in the USBCMD register */
static void ehci_set_command_bit(struct ehci_hcd *ehci, u32 bit)
{
	ehci->command |= bit;
	ehci_writel(ehci, ehci->command, &ehci->regs->command);

	/* unblock posted write */
	ehci_readl(ehci, &ehci->regs->command);
}

/* Clear a bit in the USBCMD register */
static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
{
	ehci->command &= ~bit;
	ehci_writel(ehci, ehci->command, &ehci->regs->command);

	/* unblock posted write */
	ehci_readl(ehci, &ehci->regs->command);
}

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

/*
 * EHCI timer support...  Now using hrtimers.
 *
 * Lots of different events are triggered from ehci->hrtimer.  Whenever
 * the timer routine runs, it checks each possible event; events that are
 * currently enabled and whose expiration time has passed get handled.
 * The set of enabled events is stored as a collection of bitflags in
 * ehci->enabled_hrtimer_events, and they are numbered in order of
 * increasing delay values (ranging between 1 ms and 100 ms).
 *
 * Rather than implementing a sorted list or tree of all pending events,
 * we keep track only of the lowest-numbered pending event, in
 * ehci->next_hrtimer_event.  Whenever ehci->hrtimer gets restarted, its
 * expiration time is set to the timeout value for this event.
 *
 * As a result, events might not get handled right away; the actual delay
 * could be anywhere up to twice the requested delay.  This doesn't
 * matter, because none of the events are especially time-critical.  The
 * ones that matter most all have a delay of 1 ms, so they will be
 * handled after 2 ms at most, which is okay.  In addition to this, we
 * allow for an expiration range of 1 ms.
 */

/*
 * Delay lengths for the hrtimer event types.
 * Keep this list sorted by delay length, in the same order as
 * 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 */
	1 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_POLL_DEAD */
	1125 * NSEC_PER_USEC,	/* EHCI_HRTIMER_UNLINK_INTR */
	2 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_FREE_ITDS */
	5 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_START_UNLINK_INTR */
	6 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_ASYNC_UNLINKS */
	10 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_IAA_WATCHDOG */
	10 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_PERIODIC */
	15 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_DISABLE_ASYNC */
	100 * NSEC_PER_MSEC,	/* EHCI_HRTIMER_IO_WATCHDOG */
};

/* Enable a pending hrtimer event */
static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
		bool resched)
{
	ktime_t		*timeout = &ehci->hr_timeouts[event];

	if (resched)
		*timeout = ktime_add(ktime_get(),
				ktime_set(0, event_delays_ns[event]));
	ehci->enabled_hrtimer_events |= (1 << event);

	/* Track only the lowest-numbered pending event */
	if (event < ehci->next_hrtimer_event) {
		ehci->next_hrtimer_event = event;
		hrtimer_start_range_ns(&ehci->hrtimer, *timeout,
				NSEC_PER_MSEC, HRTIMER_MODE_ABS);
	}
}


/* 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 2-4 ms */
		if (ehci->ASS_poll_count++ < 2) {
			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
			return;
		}
		ehci_dbg(ehci, "Waited too long for the async schedule status (%x/%x), giving up\n",
				want, actual);
	}
	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)
{
	unsigned	actual, want;

	/* Don't do anything if the controller isn't running (e.g., died) */
	if (ehci->rh_state != EHCI_RH_RUNNING)
		return;

	want = (ehci->command & CMD_PSE) ? STS_PSS : 0;
	actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS;

	if (want != actual) {

		/* Poll again later, but give up after about 2-4 ms */
		if (ehci->PSS_poll_count++ < 2) {
			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
			return;
		}
		ehci_dbg(ehci, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
				want, actual);
	}
	ehci->PSS_poll_count = 0;

	/* The status is up-to-date; restart or stop the schedule as needed */
	if (want == 0) {	/* Stopped */
		if (ehci->periodic_count > 0)
			ehci_set_command_bit(ehci, CMD_PSE);

	} else {		/* Running */
		if (ehci->periodic_count == 0) {

			/* Turn off the schedule after a while */
			ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_PERIODIC,
					true);
		}
	}
}

/* Turn off the periodic schedule after a brief delay */
static void ehci_disable_PSE(struct ehci_hcd *ehci)
{
	ehci_clear_command_bit(ehci, CMD_PSE);
}


/* Poll the STS_HALT status bit; see when a dead controller stops */
static void ehci_handle_controller_death(struct ehci_hcd *ehci)
{
	if (!(ehci_readl(ehci, &ehci->regs->status) & STS_HALT)) {

		/* Give up after a few milliseconds */
		if (ehci->died_poll_count++ < 5) {
			/* Try again later */
			ehci_enable_event(ehci, EHCI_HRTIMER_POLL_DEAD, true);
			return;
		}
		ehci_warn(ehci, "Waited too long for the controller to stop, giving up\n");
	}

	/* Clean up the mess */
	ehci->rh_state = EHCI_RH_HALTED;
	ehci_writel(ehci, 0, &ehci->regs->configured_flag);
	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
	ehci_work(ehci);
	end_unlink_async(ehci);

	/* Not in process context, so don't try to reset the controller */
}

/* start to unlink interrupt QHs  */
static void ehci_handle_start_intr_unlinks(struct ehci_hcd *ehci)
{
	bool		stopped = (ehci->rh_state < EHCI_RH_RUNNING);

	/*
	 * Process all the QHs on the intr_unlink list that were added
	 * before the current unlink cycle began.  The list is in
	 * temporal order, so stop when we reach the first entry in the
	 * current cycle.  But if the root hub isn't running then
	 * process all the QHs on the list.
	 */
	while (!list_empty(&ehci->intr_unlink_wait)) {
		struct ehci_qh	*qh;

		qh = list_first_entry(&ehci->intr_unlink_wait,
				struct ehci_qh, unlink_node);
		if (!stopped && (qh->unlink_cycle ==
				ehci->intr_unlink_wait_cycle))
			break;
		list_del_init(&qh->unlink_node);
		start_unlink_intr(ehci, qh);
	}

	/* Handle remaining entries later */
	if (!list_empty(&ehci->intr_unlink_wait)) {
		ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
		++ehci->intr_unlink_wait_cycle;
	}
}

/* Handle unlinked interrupt QHs once they are gone from the hardware */
static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
{
	bool		stopped = (ehci->rh_state < EHCI_RH_RUNNING);

	/*
	 * Process all the QHs on the intr_unlink list that were added
	 * before the current unlink cycle began.  The list is in
	 * temporal order, so stop when we reach the first entry in the
	 * current cycle.  But if the root hub isn't running then
	 * process all the QHs on the list.
	 */
	ehci->intr_unlinking = true;
	while (!list_empty(&ehci->intr_unlink)) {
		struct ehci_qh	*qh;

		qh = list_first_entry(&ehci->intr_unlink, struct ehci_qh,
				unlink_node);
		if (!stopped && qh->unlink_cycle == ehci->intr_unlink_cycle)
			break;
		list_del_init(&qh->unlink_node);
		end_unlink_intr(ehci, qh);
	}

	/* Handle remaining entries later */
	if (!list_empty(&ehci->intr_unlink)) {
		ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
		++ehci->intr_unlink_cycle;
	}
	ehci->intr_unlinking = false;
}


/* Start another free-iTDs/siTDs cycle */
static void start_free_itds(struct ehci_hcd *ehci)
{
	if (!(ehci->enabled_hrtimer_events & BIT(EHCI_HRTIMER_FREE_ITDS))) {
		ehci->last_itd_to_free = list_entry(
				ehci->cached_itd_list.prev,
				struct ehci_itd, itd_list);
		ehci->last_sitd_to_free = list_entry(
				ehci->cached_sitd_list.prev,
				struct ehci_sitd, sitd_list);
		ehci_enable_event(ehci, EHCI_HRTIMER_FREE_ITDS, true);
	}
}

/* Wait for controller to stop using old iTDs and siTDs */
static void end_free_itds(struct ehci_hcd *ehci)
{
	struct ehci_itd		*itd, *n;
	struct ehci_sitd	*sitd, *sn;

	if (ehci->rh_state < EHCI_RH_RUNNING) {
		ehci->last_itd_to_free = NULL;
		ehci->last_sitd_to_free = NULL;
	}

	list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
		list_del(&itd->itd_list);
		dma_pool_free(ehci->itd_pool, itd, itd->itd_dma);
		if (itd == ehci->last_itd_to_free)
			break;
	}
	list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
		list_del(&sitd->sitd_list);
		dma_pool_free(ehci->sitd_pool, sitd, sitd->sitd_dma);
		if (sitd == ehci->last_sitd_to_free)
			break;
	}

	if (!list_empty(&ehci->cached_itd_list) ||
			!list_empty(&ehci->cached_sitd_list))
		start_free_itds(ehci);
}


/* Handle lost (or very late) IAA interrupts */
static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
{
	u32 cmd, status;

	/*
	 * 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->iaa_in_progress || ehci->rh_state != EHCI_RH_RUNNING)
		return;

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

	/*
	 * If IAA is set here it either legitimately triggered
	 * after the watchdog timer expired (_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 = ehci_readl(ehci, &ehci->regs->status);
	if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
		COUNT(ehci->stats.lost_iaa);
		ehci_writel(ehci, STS_IAA, &ehci->regs->status);
	}

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


/* Enable the I/O watchdog, if appropriate */
static void turn_on_io_watchdog(struct ehci_hcd *ehci)
{
	/* Not needed if the controller isn't running or it's already enabled */
	if (ehci->rh_state != EHCI_RH_RUNNING ||
			(ehci->enabled_hrtimer_events &
				BIT(EHCI_HRTIMER_IO_WATCHDOG)))
		return;

	/*
	 * Isochronous transfers always need the watchdog.
	 * For other sorts we use it only if the flag is set.
	 */
	if (ehci->isoc_count > 0 || (ehci->need_io_watchdog &&
			ehci->async_count + ehci->intr_count > 0))
		ehci_enable_event(ehci, EHCI_HRTIMER_IO_WATCHDOG, true);
}


/*
 * Handler functions for the hrtimer event types.
 * Keep this array in the same order as the event types indexed by
 * 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_handle_controller_death,	/* EHCI_HRTIMER_POLL_DEAD */
	ehci_handle_intr_unlinks,	/* EHCI_HRTIMER_UNLINK_INTR */
	end_free_itds,			/* EHCI_HRTIMER_FREE_ITDS */
	ehci_handle_start_intr_unlinks,	/* EHCI_HRTIMER_START_UNLINK_INTR */
	unlink_empty_async,		/* EHCI_HRTIMER_ASYNC_UNLINKS */
	ehci_iaa_watchdog,		/* EHCI_HRTIMER_IAA_WATCHDOG */
	ehci_disable_PSE,		/* EHCI_HRTIMER_DISABLE_PERIODIC */
	ehci_disable_ASE,		/* EHCI_HRTIMER_DISABLE_ASYNC */
	ehci_work,			/* EHCI_HRTIMER_IO_WATCHDOG */
};

static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)
{
	struct ehci_hcd	*ehci = container_of(t, struct ehci_hcd, hrtimer);
	ktime_t		now;
	unsigned long	events;
	unsigned long	flags;
	unsigned	e;

	spin_lock_irqsave(&ehci->lock, flags);

	events = ehci->enabled_hrtimer_events;
	ehci->enabled_hrtimer_events = 0;
	ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT;

	/*
	 * Check each pending event.  If its time has expired, handle
	 * the event; otherwise re-enable it.
	 */
	now = ktime_get();
	for_each_set_bit(e, &events, EHCI_HRTIMER_NUM_EVENTS) {
		if (now.tv64 >= ehci->hr_timeouts[e].tv64)
			event_handlers[e](ehci);
		else
			ehci_enable_event(ehci, e, false);
	}

	spin_unlock_irqrestore(&ehci->lock, flags);
	return HRTIMER_NORESTART;
}
Commit	Line	Data
d58b4bcc AS	1	/*
	2	* Copyright (C) 2012 by Alan Stern
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the
	6	* Free Software Foundation; either version 2 of the License, or (at your
	7	* option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	11	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	12	* for more details.
	13	*/
	14
	15	/* This file is part of ehci-hcd.c */
	16
	17	/-------------------------------------------------------------------------/
	18
3ca9aeba AS	19	/* Set a bit in the USBCMD register */
	20	static void ehci_set_command_bit(struct ehci_hcd *ehci, u32 bit)
	21	{
	22	ehci->command \|= bit;
	23	ehci_writel(ehci, ehci->command, &ehci->regs->command);
	24
	25	/* unblock posted write */
	26	ehci_readl(ehci, &ehci->regs->command);
	27	}
	28
	29	/* Clear a bit in the USBCMD register */
	30	static void ehci_clear_command_bit(struct ehci_hcd *ehci, u32 bit)
	31	{
	32	ehci->command &= ~bit;
	33	ehci_writel(ehci, ehci->command, &ehci->regs->command);
	34
	35	/* unblock posted write */
	36	ehci_readl(ehci, &ehci->regs->command);
	37	}
	38
	39	/-------------------------------------------------------------------------/
	40
d58b4bcc AS	41	/*
	42	* EHCI timer support... Now using hrtimers.
	43	*
	44	* Lots of different events are triggered from ehci->hrtimer. Whenever
	45	* the timer routine runs, it checks each possible event; events that are
	46	* currently enabled and whose expiration time has passed get handled.
	47	* The set of enabled events is stored as a collection of bitflags in
	48	* ehci->enabled_hrtimer_events, and they are numbered in order of
	49	* increasing delay values (ranging between 1 ms and 100 ms).
	50	*
	51	* Rather than implementing a sorted list or tree of all pending events,
	52	* we keep track only of the lowest-numbered pending event, in
	53	* ehci->next_hrtimer_event. Whenever ehci->hrtimer gets restarted, its
	54	* expiration time is set to the timeout value for this event.
	55	*
	56	* As a result, events might not get handled right away; the actual delay
	57	* could be anywhere up to twice the requested delay. This doesn't
	58	* matter, because none of the events are especially time-critical. The
	59	* ones that matter most all have a delay of 1 ms, so they will be
	60	* handled after 2 ms at most, which is okay. In addition to this, we
	61	* allow for an expiration range of 1 ms.
	62	*/
	63
	64	/*
	65	* Delay lengths for the hrtimer event types.
	66	* Keep this list sorted by delay length, in the same order as
	67	* the event types indexed by enum ehci_hrtimer_event in ehci.h.
	68	*/
	69	static unsigned event_delays_ns[] = {
31446610	70	1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_ASS */
3ca9aeba	71	1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_PSS */
bf6387bc	72	1 * NSEC_PER_MSEC, /* EHCI_HRTIMER_POLL_DEAD */
df202255	73	1125 * NSEC_PER_USEC, /* EHCI_HRTIMER_UNLINK_INTR */
55934eb3	74	2 * NSEC_PER_MSEC, /* EHCI_HRTIMER_FREE_ITDS */
9118f9eb	75	5 * NSEC_PER_MSEC, /* EHCI_HRTIMER_START_UNLINK_INTR */
32830f20	76	6 * NSEC_PER_MSEC, /* EHCI_HRTIMER_ASYNC_UNLINKS */
9d938747	77	10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IAA_WATCHDOG */
3ca9aeba	78	10 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_PERIODIC */
31446610	79	15 * NSEC_PER_MSEC, /* EHCI_HRTIMER_DISABLE_ASYNC */
18aafe64	80	100 * NSEC_PER_MSEC, /* EHCI_HRTIMER_IO_WATCHDOG */
d58b4bcc AS	81	};
	82
	83	/* Enable a pending hrtimer event */
	84	static void ehci_enable_event(struct ehci_hcd *ehci, unsigned event,
	85	bool resched)
	86	{
	87	ktime_t *timeout = &ehci->hr_timeouts[event];
	88
	89	if (resched)
	90	*timeout = ktime_add(ktime_get(),
	91	ktime_set(0, event_delays_ns[event]));
	92	ehci->enabled_hrtimer_events \|= (1 << event);
	93
	94	/* Track only the lowest-numbered pending event */
	95	if (event < ehci->next_hrtimer_event) {
	96	ehci->next_hrtimer_event = event;
	97	hrtimer_start_range_ns(&ehci->hrtimer, *timeout,
	98	NSEC_PER_MSEC, HRTIMER_MODE_ABS);
	99	}
	100	}
	101
	102
31446610 AS	103	/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
	104	static void ehci_poll_ASS(struct ehci_hcd *ehci)
	105	{
	106	unsigned actual, want;
	107
	108	/* Don't enable anything if the controller isn't running (e.g., died) */
	109	if (ehci->rh_state != EHCI_RH_RUNNING)
	110	return;
	111
	112	want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
	113	actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
	114
	115	if (want != actual) {
	116
6d5df897 AS	117	/* Poll again later, but give up after about 2-4 ms */
6d5df897 AS	118	if (ehci->ASS_poll_count++ < 2) {
221f8dfc AS	119	ehci_enable_event(ehci, EHCI_HRTIMER_POLL_ASS, true);
	120	return;
	121	}
	122	ehci_dbg(ehci, "Waited too long for the async schedule status (%x/%x), giving up\n",
	123	want, actual);
31446610 AS	124	}
	125	ehci->ASS_poll_count = 0;
	126
	127	/* The status is up-to-date; restart or stop the schedule as needed */
	128	if (want == 0) { /* Stopped */
	129	if (ehci->async_count > 0)
	130	ehci_set_command_bit(ehci, CMD_ASE);
	131
	132	} else { /* Running */
	133	if (ehci->async_count == 0) {
	134
	135	/* Turn off the schedule after a while */
	136	ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_ASYNC,
	137	true);
	138	}
	139	}
	140	}
	141
	142	/* Turn off the async schedule after a brief delay */
	143	static void ehci_disable_ASE(struct ehci_hcd *ehci)
	144	{
	145	ehci_clear_command_bit(ehci, CMD_ASE);
	146	}
	147
	148
3ca9aeba AS	149	/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
	150	static void ehci_poll_PSS(struct ehci_hcd *ehci)
	151	{
	152	unsigned actual, want;
	153
	154	/* Don't do anything if the controller isn't running (e.g., died) */
	155	if (ehci->rh_state != EHCI_RH_RUNNING)
	156	return;
	157
	158	want = (ehci->command & CMD_PSE) ? STS_PSS : 0;
	159	actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS;
	160
	161	if (want != actual) {
	162
6d5df897 AS	163	/* Poll again later, but give up after about 2-4 ms */
6d5df897 AS	164	if (ehci->PSS_poll_count++ < 2) {
221f8dfc AS	165	ehci_enable_event(ehci, EHCI_HRTIMER_POLL_PSS, true);
	166	return;
	167	}
	168	ehci_dbg(ehci, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
	169	want, actual);
3ca9aeba AS	170	}
	171	ehci->PSS_poll_count = 0;
	172
	173	/* The status is up-to-date; restart or stop the schedule as needed */
	174	if (want == 0) { /* Stopped */
569b394f	175	if (ehci->periodic_count > 0)
3ca9aeba	176	ehci_set_command_bit(ehci, CMD_PSE);
3ca9aeba AS	177
	178	} else { /* Running */
	179	if (ehci->periodic_count == 0) {
	180
	181	/* Turn off the schedule after a while */
	182	ehci_enable_event(ehci, EHCI_HRTIMER_DISABLE_PERIODIC,
	183	true);
	184	}
	185	}
	186	}
	187
	188	/* Turn off the periodic schedule after a brief delay */
	189	static void ehci_disable_PSE(struct ehci_hcd *ehci)
	190	{
	191	ehci_clear_command_bit(ehci, CMD_PSE);
3ca9aeba AS	192	}
	193
	194
bf6387bc AS	195	/* Poll the STS_HALT status bit; see when a dead controller stops */
	196	static void ehci_handle_controller_death(struct ehci_hcd *ehci)
	197	{
	198	if (!(ehci_readl(ehci, &ehci->regs->status) & STS_HALT)) {
	199
	200	/* Give up after a few milliseconds */
	201	if (ehci->died_poll_count++ < 5) {
	202	/* Try again later */
	203	ehci_enable_event(ehci, EHCI_HRTIMER_POLL_DEAD, true);
	204	return;
	205	}
	206	ehci_warn(ehci, "Waited too long for the controller to stop, giving up\n");
	207	}
	208
	209	/* Clean up the mess */
	210	ehci->rh_state = EHCI_RH_HALTED;
	211	ehci_writel(ehci, 0, &ehci->regs->configured_flag);
	212	ehci_writel(ehci, 0, &ehci->regs->intr_enable);
	213	ehci_work(ehci);
3c273a05	214	end_unlink_async(ehci);
bf6387bc AS	215
	216	/* Not in process context, so don't try to reset the controller */
	217	}
	218
9118f9eb ML	219	/* start to unlink interrupt QHs */
	220	static void ehci_handle_start_intr_unlinks(struct ehci_hcd *ehci)
	221	{
	222	bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
	223
	224	/*
	225	* Process all the QHs on the intr_unlink list that were added
	226	* before the current unlink cycle began. The list is in
	227	* temporal order, so stop when we reach the first entry in the
	228	* current cycle. But if the root hub isn't running then
	229	* process all the QHs on the list.
	230	*/
	231	while (!list_empty(&ehci->intr_unlink_wait)) {
	232	struct ehci_qh *qh;
	233
	234	qh = list_first_entry(&ehci->intr_unlink_wait,
	235	struct ehci_qh, unlink_node);
	236	if (!stopped && (qh->unlink_cycle ==
	237	ehci->intr_unlink_wait_cycle))
	238	break;
	239	list_del_init(&qh->unlink_node);
	240	start_unlink_intr(ehci, qh);
	241	}
	242
	243	/* Handle remaining entries later */
	244	if (!list_empty(&ehci->intr_unlink_wait)) {
	245	ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
	246	++ehci->intr_unlink_wait_cycle;
	247	}
	248	}
bf6387bc	249
df202255 AS	250	/* Handle unlinked interrupt QHs once they are gone from the hardware */
	251	static void ehci_handle_intr_unlinks(struct ehci_hcd *ehci)
	252	{
	253	bool stopped = (ehci->rh_state < EHCI_RH_RUNNING);
	254
	255	/*
	256	* Process all the QHs on the intr_unlink list that were added
	257	* before the current unlink cycle began. The list is in
	258	* temporal order, so stop when we reach the first entry in the
	259	* current cycle. But if the root hub isn't running then
	260	* process all the QHs on the list.
	261	*/
	262	ehci->intr_unlinking = true;
6e018751 AS	263	while (!list_empty(&ehci->intr_unlink)) {
6e018751 AS	264	struct ehci_qh *qh;
df202255	265
6e018751 AS	266	qh = list_first_entry(&ehci->intr_unlink, struct ehci_qh,
6e018751 AS	267	unlink_node);
df202255 AS	268	if (!stopped && qh->unlink_cycle == ehci->intr_unlink_cycle)
df202255 AS	269	break;
9118f9eb	270	list_del_init(&qh->unlink_node);
df202255 AS	271	end_unlink_intr(ehci, qh);
	272	}
	273
	274	/* Handle remaining entries later */
6e018751	275	if (!list_empty(&ehci->intr_unlink)) {
df202255 AS	276	ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
	277	++ehci->intr_unlink_cycle;
	278	}
	279	ehci->intr_unlinking = false;
	280	}
	281
	282
55934eb3 AS	283	/* Start another free-iTDs/siTDs cycle */
	284	static void start_free_itds(struct ehci_hcd *ehci)
	285	{
	286	if (!(ehci->enabled_hrtimer_events & BIT(EHCI_HRTIMER_FREE_ITDS))) {
	287	ehci->last_itd_to_free = list_entry(
	288	ehci->cached_itd_list.prev,
	289	struct ehci_itd, itd_list);
	290	ehci->last_sitd_to_free = list_entry(
	291	ehci->cached_sitd_list.prev,
	292	struct ehci_sitd, sitd_list);
	293	ehci_enable_event(ehci, EHCI_HRTIMER_FREE_ITDS, true);
	294	}
	295	}
	296
	297	/* Wait for controller to stop using old iTDs and siTDs */
	298	static void end_free_itds(struct ehci_hcd *ehci)
	299	{
	300	struct ehci_itd itd, n;
	301	struct ehci_sitd sitd, sn;
	302
	303	if (ehci->rh_state < EHCI_RH_RUNNING) {
	304	ehci->last_itd_to_free = NULL;
	305	ehci->last_sitd_to_free = NULL;
	306	}
	307
	308	list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
	309	list_del(&itd->itd_list);
	310	dma_pool_free(ehci->itd_pool, itd, itd->itd_dma);
	311	if (itd == ehci->last_itd_to_free)
	312	break;
	313	}
	314	list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
	315	list_del(&sitd->sitd_list);
	316	dma_pool_free(ehci->sitd_pool, sitd, sitd->sitd_dma);
	317	if (sitd == ehci->last_sitd_to_free)
	318	break;
	319	}
	320
	321	if (!list_empty(&ehci->cached_itd_list) \|\|
	322	!list_empty(&ehci->cached_sitd_list))
	323	start_free_itds(ehci);
	324	}
	325
	326
9d938747 AS	327	/* Handle lost (or very late) IAA interrupts */
	328	static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
	329	{
60fd4aa7	330	u32 cmd, status;
9d938747	331
417c765a AS	332	/*
	333	* Lost IAA irqs wedge things badly; seen first with a vt8235.
	334	* So we need this watchdog, but must protect it against both
	335	* (a) SMP races against real IAA firing and retriggering, and
	336	* (b) clean HC shutdown, when IAA watchdog was pending.
	337	*/
214ac7a0	338	if (!ehci->iaa_in_progress \|\| ehci->rh_state != EHCI_RH_RUNNING)
417c765a AS	339	return;
417c765a AS	340
60fd4aa7 AS	341	/* If we get here, IAA is REALLY late. It's barely
	342	* conceivable that the system is so busy that CMD_IAAD
	343	* is still legitimately set, so let's be sure it's
	344	* clear before we read STS_IAA. (The HC should clear
	345	* CMD_IAAD when it sets STS_IAA.)
	346	*/
	347	cmd = ehci_readl(ehci, &ehci->regs->command);
9d938747	348
60fd4aa7 AS	349	/*
	350	* If IAA is set here it either legitimately triggered
	351	* after the watchdog timer expired (_way_ late, so we'll
	352	* still count it as lost) ... or a silicon erratum:
	353	* - VIA seems to set IAA without triggering the IRQ;
	354	* - IAAD potentially cleared without setting IAA.
	355	*/
	356	status = ehci_readl(ehci, &ehci->regs->status);
	357	if ((status & STS_IAA) \|\| !(cmd & CMD_IAAD)) {
	358	COUNT(ehci->stats.lost_iaa);
	359	ehci_writel(ehci, STS_IAA, &ehci->regs->status);
9d938747	360	}
60fd4aa7 AS	361
	362	ehci_dbg(ehci, "IAA watchdog: status %x cmd %x\n", status, cmd);
	363	end_unlink_async(ehci);
9d938747 AS	364	}
	365
	366
18aafe64 AS	367	/* Enable the I/O watchdog, if appropriate */
	368	static void turn_on_io_watchdog(struct ehci_hcd *ehci)
	369	{
	370	/* Not needed if the controller isn't running or it's already enabled */
	371	if (ehci->rh_state != EHCI_RH_RUNNING \|\|
	372	(ehci->enabled_hrtimer_events &
	373	BIT(EHCI_HRTIMER_IO_WATCHDOG)))
	374	return;
	375
	376	/*
	377	* Isochronous transfers always need the watchdog.
	378	* For other sorts we use it only if the flag is set.
	379	*/
	380	if (ehci->isoc_count > 0 \|\| (ehci->need_io_watchdog &&
	381	ehci->async_count + ehci->intr_count > 0))
	382	ehci_enable_event(ehci, EHCI_HRTIMER_IO_WATCHDOG, true);
	383	}
	384
	385
d58b4bcc AS	386	/*
	387	* Handler functions for the hrtimer event types.
	388	* Keep this array in the same order as the event types indexed by
	389	* enum ehci_hrtimer_event in ehci.h.
	390	*/
	391	static void (event_handlers[])(struct ehci_hcd ) = {
31446610	392	ehci_poll_ASS, /* EHCI_HRTIMER_POLL_ASS */
3ca9aeba	393	ehci_poll_PSS, /* EHCI_HRTIMER_POLL_PSS */
bf6387bc	394	ehci_handle_controller_death, /* EHCI_HRTIMER_POLL_DEAD */
df202255	395	ehci_handle_intr_unlinks, /* EHCI_HRTIMER_UNLINK_INTR */
55934eb3	396	end_free_itds, /* EHCI_HRTIMER_FREE_ITDS */
9118f9eb	397	ehci_handle_start_intr_unlinks, /* EHCI_HRTIMER_START_UNLINK_INTR */
32830f20	398	unlink_empty_async, /* EHCI_HRTIMER_ASYNC_UNLINKS */
9d938747	399	ehci_iaa_watchdog, /* EHCI_HRTIMER_IAA_WATCHDOG */
3ca9aeba	400	ehci_disable_PSE, /* EHCI_HRTIMER_DISABLE_PERIODIC */
31446610	401	ehci_disable_ASE, /* EHCI_HRTIMER_DISABLE_ASYNC */
18aafe64	402	ehci_work, /* EHCI_HRTIMER_IO_WATCHDOG */
d58b4bcc AS	403	};
	404
	405	static enum hrtimer_restart ehci_hrtimer_func(struct hrtimer *t)
	406	{
	407	struct ehci_hcd *ehci = container_of(t, struct ehci_hcd, hrtimer);
	408	ktime_t now;
	409	unsigned long events;
	410	unsigned long flags;
	411	unsigned e;
	412
	413	spin_lock_irqsave(&ehci->lock, flags);
	414
	415	events = ehci->enabled_hrtimer_events;
	416	ehci->enabled_hrtimer_events = 0;
	417	ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT;
	418
	419	/*
	420	* Check each pending event. If its time has expired, handle
	421	* the event; otherwise re-enable it.
	422	*/
	423	now = ktime_get();
	424	for_each_set_bit(e, &events, EHCI_HRTIMER_NUM_EVENTS) {
	425	if (now.tv64 >= ehci->hr_timeouts[e].tv64)
	426	event_handlers[e](ehci);
	427	else
	428	ehci_enable_event(ehci, e, false);
	429	}
	430
	431	spin_unlock_irqrestore(&ehci->lock, flags);
	432	return HRTIMER_NORESTART;
	433	}