uhci-hcd.c

h内核

	uhci_delete_queued_urb(uhci, urb);

	/* The interrupt loop will reclaim the QH's */
	uhci_remove_qh(uhci, urbp->qh);
	urbp->qh = NULL;
}

static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	unsigned long flags;
	struct urb_priv *urbp;
	unsigned int age;

	spin_lock_irqsave(&uhci->schedule_lock, flags);
	urbp = urb->hcpriv;
	if (!urbp)			/* URB was never linked! */
		goto done;
	list_del_init(&urbp->urb_list);

	uhci_unlink_generic(uhci, urb);

	age = uhci_get_current_frame_number(uhci);
	if (age != uhci->urb_remove_age) {
		uhci_remove_pending_urbps(uhci);
		uhci->urb_remove_age = age;
	}

	/* If we're the first, set the next interrupt bit */
	if (list_empty(&uhci->urb_remove_list))
		uhci_set_next_interrupt(uhci);
	list_add_tail(&urbp->urb_list, &uhci->urb_remove_list);

done:
	spin_unlock_irqrestore(&uhci->schedule_lock, flags);
	return 0;
}

static int uhci_fsbr_timeout(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct list_head *head;
	struct uhci_td *td;
	int count = 0;

	uhci_dec_fsbr(uhci, urb);

	urbp->fsbr_timeout = 1;

	/*
	 * Ideally we would want to fix qh->element as well, but it's
	 * read/write by the HC, so that can introduce a race. It's not
	 * really worth the hassle
	 */

	head = &urbp->td_list;
	list_for_each_entry(td, head, list) {
		/*
		 * Make sure we don't do the last one (since it'll have the
		 * TERM bit set) as well as we skip every so many TD's to
		 * make sure it doesn't hog the bandwidth
		 */
		if (td->list.next != head && (count % DEPTH_INTERVAL) ==
				(DEPTH_INTERVAL - 1))
			td->link |= UHCI_PTR_DEPTH;

		count++;
	}

	return 0;
}

/*
 * uhci_get_current_frame_number()
 *
 * returns the current frame number for a USB bus/controller.
 */
static unsigned int uhci_get_current_frame_number(struct uhci_hcd *uhci)
{
	return inw(uhci->io_addr + USBFRNUM);
}

static int init_stall_timer(struct usb_hcd *hcd);

static void stall_callback(unsigned long ptr)
{
	struct usb_hcd *hcd = (struct usb_hcd *)ptr;
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	struct urb_priv *up;
	unsigned long flags;
	int called_uhci_finish_completion = 0;

	spin_lock_irqsave(&uhci->schedule_lock, flags);
	if (!list_empty(&uhci->urb_remove_list) &&
	    uhci_get_current_frame_number(uhci) != uhci->urb_remove_age) {
		uhci_remove_pending_urbps(uhci);
		uhci_finish_completion(hcd, NULL);
		called_uhci_finish_completion = 1;
	}

	list_for_each_entry(up, &uhci->urb_list, urb_list) {
		struct urb *u = up->urb;

		spin_lock(&u->lock);

		/* Check if the FSBR timed out */
		if (up->fsbr && !up->fsbr_timeout && time_after_eq(jiffies, up->fsbrtime + IDLE_TIMEOUT))
			uhci_fsbr_timeout(uhci, u);

		spin_unlock(&u->lock);
	}
	spin_unlock_irqrestore(&uhci->schedule_lock, flags);

	/* Wake up anyone waiting for an URB to complete */
	if (called_uhci_finish_completion)
		wake_up_all(&uhci->waitqh);

	/* Really disable FSBR */
	if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {
		uhci->fsbrtimeout = 0;
		uhci->skel_term_qh->link = UHCI_PTR_TERM;
	}

	/* Poll for and perform state transitions */
	hc_state_transitions(uhci);
	if (unlikely(uhci->suspended_ports && uhci->state != UHCI_SUSPENDED))
		uhci_check_resume(uhci);

	init_stall_timer(hcd);
}

static int init_stall_timer(struct usb_hcd *hcd)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);

	init_timer(&uhci->stall_timer);
	uhci->stall_timer.function = stall_callback;
	uhci->stall_timer.data = (unsigned long)hcd;
	uhci->stall_timer.expires = jiffies + msecs_to_jiffies(100);
	add_timer(&uhci->stall_timer);

	return 0;
}

static void uhci_free_pending_qhs(struct uhci_hcd *uhci)
{
	struct uhci_qh *qh, *tmp;

	list_for_each_entry_safe(qh, tmp, &uhci->qh_remove_list, remove_list) {
		list_del_init(&qh->remove_list);

		uhci_free_qh(uhci, qh);
	}
}

static void uhci_free_pending_tds(struct uhci_hcd *uhci)
{
	struct uhci_td *td, *tmp;

	list_for_each_entry_safe(td, tmp, &uhci->td_remove_list, remove_list) {
		list_del_init(&td->remove_list);

		uhci_free_td(uhci, td);
	}
}

static void
uhci_finish_urb(struct usb_hcd *hcd, struct urb *urb, struct pt_regs *regs)
__releases(uhci->schedule_lock)
__acquires(uhci->schedule_lock)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);

	uhci_destroy_urb_priv(uhci, urb);

	spin_unlock(&uhci->schedule_lock);
	usb_hcd_giveback_urb(hcd, urb, regs);
	spin_lock(&uhci->schedule_lock);
}

static void uhci_finish_completion(struct usb_hcd *hcd, struct pt_regs *regs)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	struct urb_priv *urbp, *tmp;

	list_for_each_entry_safe(urbp, tmp, &uhci->complete_list, urb_list) {
		struct urb *urb = urbp->urb;

		list_del_init(&urbp->urb_list);
		uhci_finish_urb(hcd, urb, regs);
	}
}

static void uhci_remove_pending_urbps(struct uhci_hcd *uhci)
{

	/* Splice the urb_remove_list onto the end of the complete_list */
	list_splice_init(&uhci->urb_remove_list, uhci->complete_list.prev);
}

static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	unsigned long io_addr = uhci->io_addr;
	unsigned short status;
	struct urb_priv *urbp, *tmp;
	unsigned int age;

	/*
	 * Read the interrupt status, and write it back to clear the
	 * interrupt cause.  Contrary to the UHCI specification, the
	 * "HC Halted" status bit is persistent: it is RO, not R/WC.
	 */
	status = inw(io_addr + USBSTS);
	if (!(status & ~USBSTS_HCH))	/* shared interrupt, not mine */
		return IRQ_NONE;
	outw(status, io_addr + USBSTS);		/* Clear it */

	if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
		if (status & USBSTS_HSE)
			dev_err(uhci_dev(uhci), "host system error, "
					"PCI problems?\n");
		if (status & USBSTS_HCPE)
			dev_err(uhci_dev(uhci), "host controller process "
					"error, something bad happened!\n");
		if ((status & USBSTS_HCH) && uhci->state > 0) {
			dev_err(uhci_dev(uhci), "host controller halted, "
					"very bad!\n");
			/* FIXME: Reset the controller, fix the offending TD */
		}
	}

	if (status & USBSTS_RD)
		uhci->resume_detect = 1;

	spin_lock(&uhci->schedule_lock);

	age = uhci_get_current_frame_number(uhci);
	if (age != uhci->qh_remove_age)
		uhci_free_pending_qhs(uhci);
	if (age != uhci->td_remove_age)
		uhci_free_pending_tds(uhci);
	if (age != uhci->urb_remove_age)
		uhci_remove_pending_urbps(uhci);

	if (list_empty(&uhci->urb_remove_list) &&
	    list_empty(&uhci->td_remove_list) &&
	    list_empty(&uhci->qh_remove_list))
		uhci_clear_next_interrupt(uhci);
	else
		uhci_set_next_interrupt(uhci);

	/* Walk the list of pending URBs to see which ones completed
	 * (must be _safe because uhci_transfer_result() dequeues URBs) */
	list_for_each_entry_safe(urbp, tmp, &uhci->urb_list, urb_list) {
		struct urb *urb = urbp->urb;

		/* Checks the status and does all of the magic necessary */
		uhci_transfer_result(uhci, urb);
	}
	uhci_finish_completion(hcd, regs);

	spin_unlock(&uhci->schedule_lock);

	/* Wake up anyone waiting for an URB to complete */
	wake_up_all(&uhci->waitqh);

	return IRQ_HANDLED;
}

static void reset_hc(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;

	/* Turn off PIRQ, SMI, and all interrupts.  This also turns off
	 * the BIOS's USB Legacy Support.
	 */
	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
	outw(0, uhci->io_addr + USBINTR);

	/* Global reset for 50ms */
	uhci->state = UHCI_RESET;
	outw(USBCMD_GRESET, io_addr + USBCMD);
	msleep(50);
	outw(0, io_addr + USBCMD);

	/* Another 10ms delay */
	msleep(10);
	uhci->resume_detect = 0;
}

static void suspend_hc(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;

	dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
	uhci->state = UHCI_SUSPENDED;
	uhci->resume_detect = 0;
	outw(USBCMD_EGSM, io_addr + USBCMD);
}

static void wakeup_hc(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;

	switch (uhci->state) {
		case UHCI_SUSPENDED:		/* Start the resume */
			dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);

			/* Global resume for >= 20ms */
			outw(USBCMD_FGR | USBCMD_EGSM, io_addr + USBCMD);
			uhci->state = UHCI_RESUMING_1;
			uhci->state_end = jiffies + msecs_to_jiffies(20);
			break;

		case UHCI_RESUMING_1:		/* End global resume */
			uhci->state = UHCI_RESUMING_2;
			outw(0, io_addr + USBCMD);
			/* Falls through */

		case UHCI_RESUMING_2:		/* Wait for EOP to be sent */
			if (inw(io_addr + USBCMD) & USBCMD_FGR)
				break;

			/* Run for at least 1 second, and
			 * mark it configured with a 64-byte max packet */
			uhci->state = UHCI_RUNNING_GRACE;
			uhci->state_end = jiffies + HZ;
			outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP,
					io_addr + USBCMD);
			break;

		case UHCI_RUNNING_GRACE:	/* Now allowed to suspend */
			uhci->state = UHCI_RUNNING;
			break;

		default:
			break;
	}
}

static int ports_active(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;
	int connection = 0;
	int i;

	for (i = 0; i < uhci->rh_numports; i++)
		connection |= (inw(io_addr + USBPORTSC1 + i * 2) & USBPORTSC_CCS);

	return connection;
}

static int suspend_allowed(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;
	int i;

	if (to_pci_dev(uhci_dev(uhci))->vendor != PCI_VENDOR_ID_INTEL)
		return 1;

	/* Some of Intel's USB controllers have a bug that causes false
	 * resume indications if any port has an over current condition.
	 * To prevent problems, we will not allow a global suspend if
	 * any ports are OC.
	 *
	 * Some motherboards using Intel's chipsets (but not using all
	 * the USB ports) appear to hardwire the over current inputs active
	 * to disable the USB ports.
	 */

	/* check for over current condition on any port */
	for (i = 0; i < uhci->rh_numports; i++) {
		if (inw(io_addr + USBPORTSC1 + i * 2) & USBPORTSC_OC)
			return 0;
	}

	return 1;
}

static void hc_state_transitions(struct uhci_hcd *uhci)
{
	switch (uhci->state) {
		case UHCI_RUNNING:

			/* global suspend if nothing connected for 1 second */
			if (!ports_active(uhci) && suspend_allowed(uhci)) {
				uhci->state = UHCI_SUSPENDING_GRACE;
				uhci->state_end = jiffies + HZ;
			}
			break;

		case UHCI_SUSPENDING_GRACE:
			if (ports_active(uhci))
				uhci->state = UHCI_RUNNING;
			else if (time_after_eq(jiffies, uhci->state_end))
				suspend_hc(uhci);
			break;

		case UHCI_SUSPENDED:

			/* wakeup if requested by a device */
			if (uhci->resume_detect)
				wakeup_hc(uhci);
			break;

		case UHCI_RESUMING_1:
		case UHCI_RESUMING_2:
		case UHCI_RUNNING_GRACE:
			if (time_after_eq(jiffies, uhci->state_end))
				wakeup_hc(uhci);
			break;

		default:
			break;
	}
}

static int start_hc(struct uhci_hcd *uhci)
{
	unsigned long io_addr = uhci->io_addr;
	int timeout = 10;

	/*
	 * Reset the HC - this will force us to get a
	 * new notification of any already connected
	 * ports due to the virtual disconnect that it
	 * implies.
	 */
	outw(USBCMD_HCRESET, io_addr + USBCMD);
	while (inw(io_addr + USBCMD) & USBCMD_HCRESET) {
		if (--timeout < 0) {
			dev_err(uhci_dev(uhci), "USBCMD_HCRESET timed out!\n");
			return -ETIMEDOUT;
		}
		msleep(1);
	}

	/* Turn on PIRQ and all interrupts */
	pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
			USBLEGSUP_DEFAULT);
	outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
		io_addr + USBINTR);

	/* Start at frame 0 */
	outw(0, io_addr + USBFRNUM);
	outl(uhci->fl->dma_handle, io_addr + USBFLBASEADD);

	/* Run and mark it configured with a 64-byte max packet */
	uhci->state = UHCI_RUNNING_GRACE;
	uhci->state_end = jiffies + HZ;
	outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, io_addr + USBCMD);

        uhci_to_hcd(uhci)->state = USB_STATE_RUNNING;
	return 0;
}

/*
 * De-allocate all resources..
 */
static void release_uhci(struct uhci_hcd *uhci)
{
	int i;

	for (i = 0; i < UHCI_NUM_SKELQH; i++)
		if (uhci->skelqh[i]) {
			uhci_free_qh(uhci, uhci->skelqh[i]);
			uhci->skelqh[i] = NULL;
		}

	if (uhci->term_td) {
		uhci_free_td(uhci, uhci->term_td);
		uhci->term_td = NULL;
	}

	if (uhci->qh_pool) {
		dma_pool_destroy(uhci->qh_pool);
		uhci->qh_pool = NULL;
	}

	if (uhci->td_pool) {
		dma_pool_destroy(uhci->td_pool);