path: root/drivers/usb/host/ohci-q.c

// SPDX-License-Identifier: GPL-1.0+
/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
 *
 * This file is licenced under the GPL.
 */

#include <linux/irq.h>
#include <linux/slab.h>

static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
{
	int		last = urb_priv->length - 1;

	if (last >= 0) {
		int		i;
		struct td	*td;

		for (i = 0; i <= last; i++) {
			td = urb_priv->td [i];
			if (td)
				td_free (hc, td);
		}
	}

	list_del (&urb_priv->pending);
	kfree (urb_priv);
}

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

/*
 * URB goes back to driver, and isn't reissued.
 * It's completely gone from HC data structures.
 * PRECONDITION:  ohci lock held, irqs blocked.
 */
static void
finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
__releases(ohci->lock)
__acquires(ohci->lock)
{
	struct device *dev = ohci_to_hcd(ohci)->self.controller;
	struct usb_host_endpoint *ep = urb->ep;
	struct urb_priv *urb_priv;

	// ASSERT (urb->hcpriv != 0);

 restart:
	urb_free_priv (ohci, urb->hcpriv);
	urb->hcpriv = NULL;
	if (likely(status == -EINPROGRESS))
		status = 0;

	switch (usb_pipetype (urb->pipe)) {
	case PIPE_ISOCHRONOUS:
		ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
			if (quirk_amdiso(ohci))
				usb_amd_quirk_pll_enable();
			if (quirk_amdprefetch(ohci))
				sb800_prefetch(dev, 0);
		}
		break;
	case PIPE_INTERRUPT:
		ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
		break;
	}

	/* urb->complete() can reenter this HCD */
	usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
	spin_unlock (&ohci->lock);
	usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
	spin_lock (&ohci->lock);

	/* stop periodic dma if it's not needed */
	if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
		ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
		ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
	}

	/*
	 * An isochronous URB that is sumitted too late won't have any TDs
	 * (marked by the fact that the td_cnt value is larger than the
	 * actual number of TDs).  If the next URB on this endpoint is like
	 * that, give it back now.
	 */
	if (!list_empty(&ep->urb_list)) {
		urb = list_first_entry(&ep->urb_list, struct urb, urb_list);
		urb_priv = urb->hcpriv;
		if (urb_priv->td_cnt > urb_priv->length) {
			status = 0;
			goto restart;
		}
	}
}


/*-------------------------------------------------------------------------*
 * ED handling functions
 *-------------------------------------------------------------------------*/

/* search for the right schedule branch to use for a periodic ed.
 * does some load balancing; returns the branch, or negative errno.
 */
static int balance (struct ohci_hcd *ohci, int interval, int load)
{
	int	i, branch = -ENOSPC;

	/* iso periods can be huge; iso tds specify frame numbers */
	if (interval > NUM_INTS)
		interval = NUM_INTS;

	/* search for the least loaded schedule branch of that peri