/* * Universal Host Controller Interface driver for USB. * * Maintainer: Alan Stern <stern@rowland.harvard.edu> * * (C) Copyright 1999 Linus Torvalds * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com * (C) Copyright 1999 Randy Dunlap * (C) Copyright 1999 Georg Acher, acher@in.tum.de * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface * support from usb-ohci.c by Adam Richter, adam@yggdrasil.com). * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c) * (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu */ /* * Technically, updating td->status here is a race, but it's not really a * problem. The worst that can happen is that we set the IOC bit again * generating a spurious interrupt. We could fix this by creating another * QH and leaving the IOC bit always set, but then we would have to play * games with the FSBR code to make sure we get the correct order in all * the cases. I don't think it's worth the effort */ static void uhci_set_next_interrupt(struct uhci_hcd *uhci) { if (uhci->is_stopped) mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies); uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC); } static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci) { uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC); } /* * Full-Speed Bandwidth Reclamation (FSBR). * We turn on FSBR whenever a queue that wants it is advancing, * and leave it on for a short time thereafter. */ static void uhci_fsbr_on(struct uhci_hcd *uhci) { struct uhci_qh *lqh; /* The terminating skeleton QH always points back to the first * FSBR QH. Make the last async QH point to the terminating * skeleton QH. */ uhci->fsbr_is_on = 1; lqh = list_entry(uhci->skel_async_qh->node.prev, struct uhci_qh, node); lqh->link = LINK_TO_QH(uhci->skel_term_qh); } static void uhci_fsbr_off(struct uhci_hcd *uhci) { struct uhci_qh *lqh; /* Remove the link from the last async QH to the terminating * skeleton QH. */ uhci->fsbr_is_on = 0; lqh = list_entry(uhci->skel_async_qh->node.prev, struct uhci_qh, node); lqh->link = UHCI_PTR_TERM; } static void uhci_add_fsbr(struct uhci_hcd *uhci, struct urb *urb) { struct urb_priv *urbp = urb->hcpriv; if (!(urb->transfer_flags & URB_NO_FSBR)) urbp->fsbr = 1; } static void uhci_urbp_wants_fsbr(struct uhci_hcd *uhci, struct urb_priv *urbp) { if (urbp->fsbr) { uhci->fsbr_is_wanted = 1; if (!uhci->fsbr_is_on) uhci_fsbr_on(uhci); else if (uhci->fsbr_expiring) { uhci->fsbr_expiring = 0; del_timer(&uhci->fsbr_timer); } } } static void uhci_fsbr_timeout(unsigned long _uhci) { struct uhci_hcd *uhci = (struct uhci_hcd *) _uhci; unsigned long flags; spin_lock_irqsave(&uhci->lock, flags); if (uhci->fsbr_expiring) { uhci->fsbr_expiring = 0; uhci_fsbr_off(uhci); } spin_unlock_irqrestore(&uhci->lock, flags); } static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci) { dma_addr_t dma_handle; struct uhci_td *td; td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle); if (!td) return NULL; td->dma_handle = dma_handle; td->frame = -1; INIT_LIST_HEAD(&td->list); INIT_LIST_HEAD(&td->fl_list); return td; } static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td) { if (!list_empty(&td->list)) dev_WARN(uhci_dev(uhci), "td %p still in list!\n", td); if (!list_empty(&td->fl_list)) dev_WARN(uhci_dev(uhci), "td %p still in fl_list!\n", td); dma_pool_free(uhci->td_pool, td, td->dma_handle); } static inline void uhci_fill_td(struct uhci_td *td, u32 status, u32 token, u32 buffer) { td->status = cpu_to_le32(status); td->token = cpu_to_le32(token); td->buffer = cpu_to_le32(buffer); } static void uhci_add_td_to_urbp(struct uhci_td *td, struct urb_priv *urbp) { list_add_tail(&td->list, &urbp->td_list); } static void uhci_remove_td_from_urbp(struct uhci_td *td) { list_del_init(&td->list); } /* * We insert Isochronous URBs directly into the frame list at the beginning */ static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci, struct uhci_td *td, unsigned framenum) { framenum &= (UHCI_NUMFRAMES - 1); td->frame = framenum; /* Is there a TD already mapped there? */ if (uhci->frame_cpu[framenum]) { struct uhci_td *ftd, *ltd; ftd = uhci->frame_cpu[framenum]; ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list); list_add_tail(&td->fl_list, &ftd->fl_list); td->link = ltd->link; wmb(); ltd->link = LINK_TO_TD(td); } else { td->link = uhci->frame[framenum]; wmb(); uhci->frame[framenum] = LINK_TO_TD(td); uhci->frame_cpu[framenum] = td; } } static inline void uhci_remove_td_from_frame_list(struct uhci_hcd *uhci, struct uhci_td *td) { /* If it's not inserted, don't remove it */ if (td->frame == -1) { WARN_ON(!list_empty(&td->fl_list)); return; } if (uhci->frame_cpu[td->frame] == td) { if (list_empty(&td->fl_list)) { uhci->frame[td->frame] = td->link; uhci->frame_cpu[td->frame] = NULL; } else { struct uhci_td *ntd; ntd = list_entry(td->fl_list.next, struct uhci_td, fl_list); uhci->frame[td->frame] = LINK_TO_TD(ntd); uhci->frame_cpu[td->frame] = ntd; } } else { struct uhci_td *ptd; ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list); ptd->link = td->link; } list_del_init(&td->fl_list); td->frame = -1; } static inline void uhci_remove_tds_from_frame(struct uhci_hcd *uhci, unsigned int framenum) { struct uhci_td *ftd, *ltd; framenum &= (UHCI_NUMFRAMES - 1); ftd = uhci->frame_cpu[framenum]; if (ftd) { ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list); uhci->frame[framenum] = ltd->link; uhci->frame_cpu[framenum] = NULL; while (!list_empty(&ftd->fl_list)) list_del_init(ftd->fl_list.prev); } } /* * Remove all the TDs for an Isochronous URB from the frame list */ static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb) { struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv; struct uhci_td *td; list_for_each_entry(td, &urbp->td_list, list) uhci_remove_td_from_frame_list(uhci, td); } static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci, struct usb_device *udev, struct usb_host_endpoint *hep) { dma_addr_t dma_handle; struct uhci_qh *qh; qh = dma_pool_alloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle); if (!qh) return NULL; memset(qh, 0, sizeof(*qh)); qh->dma_handle = dma_handle; qh->element = UHCI_PTR_TERM; qh->link = UHCI_PTR_TERM; INIT_LIST_HEAD(&qh->queue); INIT_LIST_HEAD(&qh->node); if (udev) { /* Normal QH */ qh->type = hep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; if (qh->type != USB_ENDPOINT_XFER_ISOC) { qh->dummy_td = uhci_alloc_td(uhci); if (!qh->dummy_td) { dma_pool_free(uhci->qh_pool, qh, dma_handle); return NULL; } } qh->state = QH_STATE_IDLE; qh->hep = hep; qh->udev = udev; hep->hcpriv = qh; if (qh->type == USB_ENDPOINT_XFER_INT || qh->type == USB_ENDPOINT_XFER_ISOC) qh->load = usb_calc_bus_time(udev->speed, usb_endpoint_dir_in(&hep->desc), qh->type == USB_ENDPOINT_XFER_ISOC, le16_to_cpu(hep->desc.wMaxPacketSize)) / 1000 + 1; } else { /* Skeleton QH */ qh->state = QH_STATE_ACTIVE; qh->type = -1; } return qh; } static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) { WARN_ON(qh->state != QH_STATE_IDLE && qh->udev); if (!list_empty(&qh->queue)) dev_WARN(uhci_dev(uhci), "qh %p list not empty!\n", qh); list_del(&qh->node); if (qh->udev) { qh->hep->hcpriv = NULL; if (qh->dummy_td) uhci_free_td(uhci, qh->dummy_td); } dma_pool_free(uhci->qh_pool, qh, qh->dma_handle); } /* * When a queue is stopped and a dequeued URB is given back, adjust * the previous TD link (if the URB isn't first on the queue) or * save its toggle value (if it is first and is currently executing). * * Returns 0 if the URB should not yet be given back, 1 otherwise. */ static int uhci_cleanup_queue(struct uhci_hcd *uhci, struct uhci_qh *qh, struct urb *urb) { struct urb_priv *urbp = urb->hcpriv; struct uhci_td *td; int ret = 1; /* Isochronous pipes don't use toggles and their TD link pointers * get adjusted during uhci_urb_dequeue(). But since their queues * cannot truly be stopped, we have to watch out for dequeues * occurring after the nominal unlink frame. */ if (qh->type == USB_ENDPOINT_XFER_ISOC) { ret = (uhci->frame_number + uhci->is_stopped != qh->unlink_frame); goto done; } /* If the URB isn't first on its queue, adjust the link pointer * of the last TD in the previous URB. The toggle doesn't need * to be saved since this URB can't be executing yet. */ if (qh->queue.next != &urbp->node) { struct urb_priv *purbp; struct uhci_td *ptd; purbp = list_entry(urbp->node.prev, struct urb_priv, node); WARN_ON(list_empty(&purbp->td_list)); ptd = list_entry(purbp->td_list.prev, struct uhci_td, list); td = list_entry(urbp->td_list.prev, struct uhci_td, list); ptd->link = td->link; goto done; } /* If the QH element pointer is UHCI_PTR_TERM then then currently * executing URB has already been unlinked, so this one isn't it. */ if (qh_element(qh) == UHCI_PTR_TERM) goto done; qh->element = UHCI_PTR_TERM; /* Control pipes don't have to worry about toggles */ if (qh->type == USB_ENDPOINT_XFER_CONTROL) goto done; /* Save the next toggle value */ WARN_ON(list_empty(&urbp->td_list)); td = list_entry(urbp->td_list.next, struct uhci_td, list); qh->needs_fixup = 1; qh->initial_toggle = uhci_toggle(td_token(td)); done: return ret; } /* * Fix up the data toggles for URBs in a queue, when one of them * terminates early (short transfer, error, or dequeued). */ static void uhci_fixup_toggles(struct uhci_qh *qh, int skip_first) { struct urb_priv *urbp = NULL; struct uhci_td *td; unsigned int toggle = qh->initial_toggle; unsigned int pipe; /* Fixups for a short transfer start with the second URB in the * queue (the short URB is the first). */ if (skip_first) urbp = list_entry(qh->queue.next, struct urb_priv, node); /* When starting with the first URB, if the QH element pointer is * still valid then we know the URB's toggles are okay. */ else if (qh_element(qh) != UHCI_PTR_TERM) toggle = 2; /* Fix up the toggle for the URBs in the queue. Normally this * loop won't run more than once: When an error or short transfer * occurs, the queue usually gets emptied. */ urbp = list_prepare_entry(urbp, &qh->queue, node); list_for_each_entry_continue(urbp, &qh->queue, node) { /* If the first TD has the right toggle value, we don't * need to change any toggles in this URB */ td = list_entry(urbp->td_list.next, struct uhci_td, list); if (toggle > 1 || uhci_toggle(td_token(td)) == toggle) { td = list_entry(urbp->td_list.prev, struct uhci_td, list); toggle = uhci_toggle(td_token(td)) ^ 1; /* Otherwise all the toggles in the URB have to be switched */ } else { list_for_each_entry(td, &urbp->td_list, list) { td->token ^= __constant_cpu_to_le32( TD_TOKEN_TOGGLE); toggle ^= 1; } } } wmb(); pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe; usb_settoggle(qh->udev, usb_pipeendpoint(pipe), usb_pipeout(pipe), toggle); qh->needs_fixup = 0; } /* * Link an Isochronous QH into its skeleton's list */ static inline void link_iso(struct uhci_hcd *uhci, struct uhci_qh *qh) { list_add_tail(&qh->node, &uhci->skel_iso_qh->node); /* Isochronous QHs aren't linked by the hardware */ } /* * Link a high-period interrupt QH into the schedule at the end of its * skeleton's list */ static void link_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct uhci_qh *pqh; list_add_tail(&qh->node, &uhci->skelqh[qh->skel]->node); pqh = list_entry(qh->node.prev, struct uhci_qh, node); qh->link = pqh->link; wmb(); pqh->link = LINK_TO_QH(qh); } /* * Link a period-1 interrupt or async QH into the schedule at the * correct spot in the async skeleton's list, and update the FSBR link */ static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct uhci_qh *pqh; __le32 link_to_new_qh; /* Find the predecessor QH for our new one and insert it in the list. * The list of QHs is expected to be short, so linear search won't * take too long. */ list_for_each_entry_reverse(pqh, &uhci->skel_async_qh->node, node) { if (pqh->skel <= qh->skel) break; } list_add(&qh->node, &pqh->node); /* Link it into the schedule */ qh->link = pqh->link; wmb(); link_to_new_qh = LINK_TO_QH(qh); pqh->link = link_to_new_qh; /* If this is now the first FSBR QH, link the terminating skeleton * QH to it. */ if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR) uhci->skel_term_qh->link = link_to_new_qh; } /* * Put a QH on the schedule in both hardware and software */ static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) { WARN_ON(list_empty(&qh->queue)); /* Set the element pointer if it isn't set already. * This isn't needed for Isochronous queues, but it doesn't hurt. */ if (qh_element(qh) == UHCI_PTR_TERM) { struct urb_priv *urbp = list_entry(qh->queue.next, struct urb_priv, node); struct uhci_td *td = list_entry(urbp->td_list.next, struct uhci_td, list); qh->element = LINK_TO_TD(td); } /* Treat the queue as if it has just advanced */ qh->wait_expired = 0; qh->advance_jiffies = jiffies; if (qh->state == QH_STATE_ACTIVE) return; qh->state = QH_STATE_ACTIVE; /* Move the QH from its old list to the correct spot in the appropriate * skeleton's list */ if (qh == uhci->next_qh) uhci->next_qh = list_entry(qh->node.next, struct uhci_qh, node); list_del(&qh->node); if (qh->skel == SKEL_ISO) link_iso(uhci, qh); else if (qh->skel < SKEL_ASYNC) link_interrupt(uhci, qh); else link_async(uhci, qh); } /* * Unlink a high-period interrupt QH from the schedule */ static void unlink_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct uhci_qh *pqh; pqh = list_entry(qh->node.prev, struct uhci_qh, node); pqh->link = qh->link; mb(); } /* * Unlink a period-1 interrupt or async QH from the schedule */ static void unlink_async(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct uhci_qh *pqh; __le32 link_to_next_qh = qh->link; pqh = list_entry(qh->node.prev, struct uhci_qh, node); pqh->link = link_to_next_qh; /* If this was the old first FSBR QH, link the terminating skeleton * QH to the next (new first FSBR) QH. */ if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR) uhci->skel_term_qh->link = link_to_next_qh; mb(); } /* * Take a QH off the hardware schedule */ static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) { if (qh->state == QH_STATE_UNLINKING) return; WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev); qh->state = QH_STATE_UNLINKING; /* Unlink the QH from the schedule and record when we did it */ if (qh->skel == SKEL_ISO) ; else if (qh->skel < SKEL_ASYNC) unlink_interrupt(uhci, qh); else unlink_async(uhci, qh); uhci_get_current_frame_number(uhci); qh->unlink_frame = uhci->frame_number; /* Force an interrupt so we know when the QH is fully unlinked */ if (list_empty(&uhci->skel_unlink_qh->node)) uhci_set_next_interrupt(uhci); /* Move the QH from its old list to the end of the unlinking list */ if (qh == uhci->next_qh) uhci->next_qh = list_entry(qh->node.next, struct uhci_qh, node); list_move_tail(&qh->node, &uhci->skel_unlink_qh->node); } /* * When we and the controller are through with a QH, it becomes IDLE. * This happens when a QH has been off the schedule (on the unlinking * list) for more than one frame, or when an error occurs while adding * the first URB onto a new QH. */ static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh) { WARN_ON(qh->state == QH_STATE_ACTIVE); if (qh == uhci->next_qh) uhci->next_qh = list_entry(qh->node.next, struct uhci_qh, node); list_move(&qh->node, &uhci->idle_qh_list); qh->state = QH_STATE_IDLE; /* Now that the QH is idle, its post_td isn't being used */ if (qh->post_td) { uhci_free_td(uhci, qh->post_td); qh->post_td = NULL; } /* If anyone is waiting for a QH to become idle, wake them up */ if (uhci->num_waiting) wake_up_all(&uhci->waitqh); } /* * Find the highest existing bandwidth load for a given phase and period. */ static int uhci_highest_load(struct uhci_hcd *uhci, int phase, int period) { int highest_load = uhci->load[phase]; for (phase += period; phase < MAX_PHASE; phase += period) highest_load = max_t(int, highest_load, uhci->load[phase]); return highest_load; } /* * Set qh->phase to the optimal phase for a periodic transfer and * check whether the bandwidth requirement is acceptable. */ static int uhci_check_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh) { int minimax_load; /* Find the optimal phase (unless it is already set) and get * its load value. */ if (qh->phase >= 0) minimax_load = uhci_highest_load(uhci, qh->phase, qh->period); else { int phase, load; int max_phase = min_t(int, MAX_PHASE, qh->period); qh->phase = 0; minimax_load = uhci_highest_load(uhci, qh->phase, qh->period); for (phase = 1; phase < max_phase; ++phase) { load = uhci_highest_load(uhci, phase, qh->period); if (load < minimax_load) { minimax_load = load; qh->phase = phase; } } } /* Maximum allowable periodic bandwidth is 90%, or 900 us per frame */ if (minimax_load + qh->load > 900) { dev_dbg(uhci_dev(uhci), "bandwidth allocation failed: " "period %d, phase %d, %d + %d us\n", qh->period, qh->phase, minimax_load, qh->load); return -ENOSPC; } return 0; } /* * Reserve a periodic QH's bandwidth in the schedule */ static void uhci_reserve_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh) { int i; int load = qh->load; char *p = "??"; for (i = qh->phase; i < MAX_PHASE; i += qh->period) { uhci->load[i] += load; uhci->total_load += load; } uhci_to_hcd(uhci)->self.bandwidth_allocated = uhci->total_load / MAX_PHASE; switch (qh->type) { case USB_ENDPOINT_XFER_INT: ++uhci_to_hcd(uhci)->self.bandwidth_int_reqs; p = "INT"; break; case USB_ENDPOINT_XFER_ISOC: ++uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs; p = "ISO"; break; } qh->bandwidth_reserved = 1; dev_dbg(uhci_dev(uhci), "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n", "reserve", qh->udev->devnum, qh->hep->desc.bEndpointAddress, p, qh->period, qh->phase, load); } /* * Release a periodic QH's bandwidth reservation */ static void uhci_release_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh) { int i; int load = qh->load; char *p = "??"; for (i = qh->phase; i < MAX_PHASE; i += qh->period) { uhci->load[i] -= load; uhci->total_load -= load; } uhci_to_hcd(uhci)->self.bandwidth_allocated = uhci->total_load / MAX_PHASE; switch (qh->type) { case USB_ENDPOINT_XFER_INT: --uhci_to_hcd(uhci)->self.bandwidth_int_reqs; p = "INT"; break; case USB_ENDPOINT_XFER_ISOC: --uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs; p = "ISO"; break; } qh->bandwidth_reserved = 0; dev_dbg(uhci_dev(uhci), "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n", "release", qh->udev->devnum, qh->hep->desc.bEndpointAddress, p, qh->period, qh->phase, load); } static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci, struct urb *urb) { struct urb_priv *urbp; urbp = kmem_cache_zalloc(uhci_up_cachep, GFP_ATOMIC); if (!urbp) return NULL; urbp->urb = urb; urb->hcpriv = urbp; INIT_LIST_HEAD(&urbp->node); INIT_LIST_HEAD(&urbp->td_list); return urbp; } static void uhci_free_urb_priv(struct uhci_hcd *uhci, struct urb_priv *urbp) { struct uhci_td *td, *tmp; if (!list_empty(&urbp->node)) dev_WARN(uhci_dev(uhci), "urb %p still on QH's list!\n", urbp->urb); list_for_each_entry_safe(td, tmp, &urbp->td_list, list) { uhci_remove_td_from_urbp(td); uhci_free_td(uhci, td); } kmem_cache_free(uhci_up_cachep, urbp); } /* * Map status to standard result codes * * <status> is (td_status(td) & 0xF60000), a.k.a. * uhci_status_bits(td_status(td)). * Note: <status> does not include the TD_CTRL_NAK bit. * <dir_out> is True for output TDs and False for input TDs. */ static int uhci_map_status(int status, int dir_out) { if (!status) return 0; if (status & TD_CTRL_BITSTUFF) /* Bitstuff error */ return -EPROTO; if (status & TD_CTRL_CRCTIMEO) { /* CRC/Timeout */ if (dir_out) return -EPROTO; else return -EILSEQ; } if (status & TD_CTRL_BABBLE) /* Babble */ return -EOVERFLOW; if (status & TD_CTRL_DBUFERR) /* Buffer error */ return -ENOSR; if (status & TD_CTRL_STALLED) /* Stalled */ return -EPIPE; return 0; } /* * Control transfers */ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, struct uhci_qh *qh) { struct uhci_td *td; unsigned long destination, status; int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize); int len = urb->transfer_buffer_length; dma_addr_t data = urb->transfer_dma; __le32 *plink; struct urb_priv *urbp = urb->hcpriv; int skel; /* The "pipe" thing contains the destination in bits 8--18 */ destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP; /* 3 errors, dummy TD remains inactive */ status = uhci_maxerr(3); if (urb->dev->speed == USB_SPEED_LOW) status |= TD_CTRL_LS; /* * Build the TD for the control request setup packet */ td = qh->dummy_td; uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status, destination | uhci_explen(8), urb->setup_dma); plink = &td->link; status |= TD_CTRL_ACTIVE; /* * If direction is "send", change the packet ID from SETUP (0x2D) * to OUT (0xE1). Else change it from SETUP to IN (0x69) and * set Short Packet Detect (SPD) for all data packets. * * 0-length transfers always get treated as "send". */ if (usb_pipeout(urb->pipe) || len == 0) destination ^= (USB_PID_SETUP ^ USB_PID_OUT); else { destination ^= (USB_PID_SETUP ^ USB_PID_IN); status |= TD_CTRL_SPD; } /* * Build the DATA TDs */ while (len > 0) { int pktsze = maxsze; if (len <= pktsze) { /* The last data packet */ pktsze = len; status &= ~TD_CTRL_SPD; } td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); /* Alternate Data0/1 (start with Data1) */ destination ^= TD_TOKEN_TOGGLE; uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status, destination | uhci_explen(pktsze), data); plink = &td->link; data += pktsze; len -= pktsze; } /* * Build the final TD for control status */ td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); /* Change direction for the status transaction */ destination ^= (USB_PID_IN ^ USB_PID_OUT); destination |= TD_TOKEN_TOGGLE; /* End in Data1 */ uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status | TD_CTRL_IOC, destination | uhci_explen(0), 0); plink = &td->link; /* * Build the new dummy TD and activate the old one */ td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0); wmb(); qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE); qh->dummy_td = td; /* Low-speed transfers get a different queue, and won't hog the bus. * Also, some devices enumerate better without FSBR; the easiest way * to do that is to put URBs on the low-speed queue while the device * isn't in the CONFIGURED state. */ if (urb->dev->speed == USB_SPEED_LOW || urb->dev->state != USB_STATE_CONFIGURED) skel = SKEL_LS_CONTROL; else { skel = SKEL_FS_CONTROL; uhci_add_fsbr(uhci, urb); } if (qh->state != QH_STATE_ACTIVE) qh->skel = skel; urb->actual_length = -8; /* Account for the SETUP packet */ return 0; nomem: /* Remove the dummy TD from the td_list so it doesn't get freed */ uhci_remove_td_from_urbp(qh->dummy_td); return -ENOMEM; } /* * Common submit for bulk and interrupt */ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, struct uhci_qh *qh) { struct uhci_td *td; unsigned long destination, status; int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize); int len = urb->transfer_buffer_length; dma_addr_t data = urb->transfer_dma; __le32 *plink; struct urb_priv *urbp = urb->hcpriv; unsigned int toggle; if (len < 0) return -EINVAL; /* The "pipe" thing contains the destination in bits 8--18 */ destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe); toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe), usb_pipeout(urb->pipe)); /* 3 errors, dummy TD remains inactive */ status = uhci_maxerr(3); if (urb->dev->speed == USB_SPEED_LOW) status |= TD_CTRL_LS; if (usb_pipein(urb->pipe)) status |= TD_CTRL_SPD; /* * Build the DATA TDs */ plink = NULL; td = qh->dummy_td; do { /* Allow zero length packets */ int pktsze = maxsze; if (len <= pktsze) { /* The last packet */ pktsze = len; if (!(urb->transfer_flags & URB_SHORT_NOT_OK)) status &= ~TD_CTRL_SPD; } if (plink) { td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); } uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status, destination | uhci_explen(pktsze) | (toggle << TD_TOKEN_TOGGLE_SHIFT), data); plink = &td->link; status |= TD_CTRL_ACTIVE; data += pktsze; len -= maxsze; toggle ^= 1; } while (len > 0); /* * URB_ZERO_PACKET means adding a 0-length packet, if direction * is OUT and the transfer_length was an exact multiple of maxsze, * hence (len = transfer_length - N * maxsze) == 0 * however, if transfer_length == 0, the zero packet was already * prepared above. */ if ((urb->transfer_flags & URB_ZERO_PACKET) && usb_pipeout(urb->pipe) && len == 0 && urb->transfer_buffer_length > 0) { td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status, destination | uhci_explen(0) | (toggle << TD_TOKEN_TOGGLE_SHIFT), data); plink = &td->link; toggle ^= 1; } /* Set the interrupt-on-completion flag on the last packet. * A more-or-less typical 4 KB URB (= size of one memory page) * will require about 3 ms to transfer; that's a little on the * fast side but not enough to justify delaying an interrupt * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT * flag setting. */ td->status |= __constant_cpu_to_le32(TD_CTRL_IOC); /* * Build the new dummy TD and activate the old one */ td = uhci_alloc_td(uhci); if (!td) goto nomem; *plink = LINK_TO_TD(td); uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0); wmb(); qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE); qh->dummy_td = td; usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), usb_pipeout(urb->pipe), toggle); return 0; nomem: /* Remove the dummy TD from the td_list so it doesn't get freed */ uhci_remove_td_from_urbp(qh->dummy_td); return -ENOMEM; } static int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, struct uhci_qh *qh) { int ret; /* Can't have low-speed bulk transfers */ if (urb->dev->speed == USB_SPEED_LOW) return -EINVAL; if (qh->state != QH_STATE_ACTIVE) qh->skel = SKEL_BULK; ret = uhci_submit_common(uhci, urb, qh); if (ret == 0) uhci_add_fsbr(uhci, urb); return ret; } static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb, struct uhci_qh *qh) { int ret; /* USB 1.1 interrupt transfers only involve one packet per interval. * Drivers can submit URBs of any length, but longer ones will need * multiple intervals to complete. */ if (!qh->bandwidth_reserved) { int exponent; /* Figure out which power-of-two queue to use */ for (exponent = 7; exponent >= 0; --exponent) { if ((1 << exponent) <= urb->interval) break; } if (exponent < 0) return -EINVAL; /* If the slot is full, try a lower period */ do { qh->period = 1 << exponent; qh->skel = SKEL_INDEX(exponent); /* For now, interrupt phase is fixed by the layout * of the QH lists. */ qh->phase = (qh->period / 2) & (MAX_PHASE - 1); ret = uhci_check_bandwidth(uhci, qh); } while (ret != 0 && --exponent >= 0); if (ret) return ret; } else if (qh->period > urb->interval) return -EINVAL; /* Can't decrease the period */ ret = uhci_submit_common(uhci, urb, qh); if (ret == 0) { urb->interval = qh->period; if (!qh->bandwidth_reserved) uhci_reserve_bandwidth(uhci, qh); } return ret; } /* * Fix up the data structures following a short transfer */ static int uhci_fixup_short_transfer(struct uhci_hcd *uhci, struct uhci_qh *qh, struct urb_priv *urbp) { struct uhci_td *td; struct list_head *tmp; int ret; td = list_entry(urbp->td_list.prev, struct uhci_td, list); if (qh->type == USB_ENDPOINT_XFER_CONTROL) { /* When a control transfer is short, we have to restart * the queue at the status stage transaction, which is * the last TD. */ WARN_ON(list_empty(&urbp->td_list)); qh->element = LINK_TO_TD(td); tmp = td->list.prev; ret = -EINPROGRESS; } else { /* When a bulk/interrupt transfer is short, we have to * fix up the toggles of the following URBs on the queue * before restarting the queue at the next URB. */ qh->initial_toggle = uhci_toggle(td_token(qh->post_td)) ^ 1; uhci_fixup_toggles(qh, 1); if (list_empty(&urbp->td_list)) td = qh->post_td; qh->element = td->link; tmp = urbp->td_list.prev; ret = 0; } /* Remove all the TDs we skipped over, from tmp back to the start */ while (tmp != &urbp->td_list) { td = list_entry(tmp, struct uhci_td, list); tmp = tmp->prev; uhci_remove_td_from_urbp(td); uhci_free_td(uhci, td); } return ret; } /* * Common result for control, bulk, and interrupt */ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb) { struct urb_priv *urbp = urb->hcpriv; struct uhci_qh *qh = urbp->qh; struct uhci_td *td, *tmp; unsigned status; int ret = 0; list_for_each_entry_safe(td, tmp, &urbp->td_list, list) { unsigned int ctrlstat; int len; ctrlstat = td_status(td); status = uhci_status_bits(ctrlstat); if (status & TD_CTRL_ACTIVE) return -EINPROGRESS; len = uhci_actual_length(ctrlstat); urb->actual_length += len; if (status) { ret = uhci_map_status(status, uhci_packetout(td_token(td))); if ((debug == 1 && ret != -EPIPE) || debug > 1) { /* Some debugging code */ dev_dbg(&urb->dev->dev, "%s: failed with status %x\n", __func__, status); if (debug > 1 && errbuf) { /* Print the chain for debugging */ uhci_show_qh(uhci, urbp->qh, errbuf, ERRBUF_LEN, 0); lprintk(errbuf); } } /* Did we receive a short packet? */ } else if (len < uhci_expected_length(td_token(td))) { /* For control transfers, go to the status TD if * this isn't already the last data TD */ if (qh->type == USB_ENDPOINT_XFER_CONTROL) { if (td->list.next != urbp->td_list.prev) ret = 1; } /* For bulk and interrupt, this may be an error */ else if (urb->transfer_flags & URB_SHORT_NOT_OK) ret = -EREMOTEIO; /* Fixup needed only if this isn't the URB's last TD */ else if (&td->list != urbp->td_list.prev) ret = 1; } uhci_remove_td_from_urbp(td); if (qh->post_td) uhci_free_td(uhci, qh->post_td); qh->post_td = td; if (ret != 0) goto err; } return ret; err: if (ret < 0) { /* Note that the queue has stopped and save * the next toggle value */ qh->element = UHCI_PTR_TERM; qh->is_stopped = 1; qh->needs_fixup = (qh->type != USB_ENDPOINT_XFER_CONTROL); qh->initial_toggle = uhci_toggle(td_token(td)) ^ (ret == -EREMOTEIO); } else /* Short packet received */ ret = uhci_fixup_short_transfer(uhci, qh, urbp); return ret; } /* * Isochronous transfers */ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb, struct uhci_qh *qh) { struct uhci_td *td = NULL; /* Since urb->number_of_packets > 0 */ int i, frame; unsigned long destination, status; struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv; /* Values must not be too big (could overflow below) */ if (urb->interval >= UHCI_NUMFRAMES || urb->number_of_packets >= UHCI_NUMFRAMES) return -EFBIG; /* Check the period and figure out the starting frame number */ if (!qh->bandwidth_reserved) { qh->period = urb->interval; if (urb->transfer_flags & URB_ISO_ASAP) { qh->phase = -1; /* Find the best phase */ i = uhci_check_bandwidth(uhci, qh); if (i) return i; /* Allow a little time to allocate the TDs */ uhci_get_current_frame_number(uhci); frame = uhci->frame_number + 10; /* Move forward to the first frame having the * correct phase */ urb->start_frame = frame + ((qh->phase - frame) & (qh->period - 1)); } else { i = urb->start_frame - uhci->last_iso_frame; if (i <= 0 || i >= UHCI_NUMFRAMES) return -EINVAL; qh->phase = urb->start_frame & (qh->period - 1); i = uhci_check_bandwidth(uhci, qh); if (i) return i; } } else if (qh->period != urb->interval) { return -EINVAL; /* Can't change the period */ } else { /* Find the next unused frame */ if (list_empty(&qh->queue)) { frame = qh->iso_frame; } else { struct urb *lurb; lurb = list_entry(qh->queue.prev, struct urb_priv, node)->urb; frame = lurb->start_frame + lurb->number_of_packets * lurb->interval; } if (urb->transfer_flags & URB_ISO_ASAP) { /* Skip some frames if necessary to insure * the start frame is in the future. */ uhci_get_current_frame_number(uhci); if (uhci_frame_before_eq(frame, uhci->frame_number)) { frame = uhci->frame_number + 1; frame += ((qh->phase - frame) & (qh->period - 1)); } } /* Otherwise pick up where the last URB leaves off */ urb->start_frame = frame; } /* Make sure we won't have to go too far into the future */ if (uhci_frame_before_eq(uhci->last_iso_frame + UHCI_NUMFRAMES, urb->start_frame + urb->number_of_packets * urb->interval)) return -EFBIG; status = TD_CTRL_ACTIVE | TD_CTRL_IOS; destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe); for (i = 0; i < urb->number_of_packets; i++) { td = uhci_alloc_td(uhci); if (!td) return -ENOMEM; uhci_add_td_to_urbp(td, urbp); uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length), urb->transfer_dma + urb->iso_frame_desc[i].offset); } /* Set the interrupt-on-completion flag on the last packet. */ td->status |= __constant_cpu_to_le32(TD_CTRL_IOC); /* Add the TDs to the frame list */ frame = urb->start_frame; list_for_each_entry(td, &urbp->td_list, list) { uhci_insert_td_in_frame_list(uhci, td, frame); frame += qh->period; } if (list_empty(&qh->queue)) { qh->iso_packet_desc = &urb->iso_frame_desc[0]; qh->iso_frame = urb->start_frame; } qh->skel = SKEL_ISO; if (!qh->bandwidth_reserved) uhci_reserve_bandwidth(uhci, qh); return 0; } static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb) { struct uhci_td *td, *tmp; struct urb_priv *urbp = urb->hcpriv; struct uhci_qh *qh = urbp->qh; list_for_each_entry_safe(td, tmp, &urbp->td_list, list) { unsigned int ctrlstat; int status; int actlength; if (uhci_frame_before_eq(uhci->cur_iso_frame, qh->iso_frame)) return -EINPROGRESS; uhci_remove_tds_from_frame(uhci, qh->iso_frame); ctrlstat = td_status(td); if (ctrlstat & TD_CTRL_ACTIVE) { status = -EXDEV; /* TD was added too late? */ } else { status = uhci_map_status(uhci_status_bits(ctrlstat), usb_pipeout(urb->pipe)); actlength = uhci_actual_length(ctrlstat); urb->actual_length += actlength; qh->iso_packet_desc->actual_length = actlength; qh->iso_packet_desc->status = status; } if (status) urb->error_count++; uhci_remove_td_from_urbp(td); uhci_free_td(uhci, td); qh->iso_frame += qh->period; ++qh->iso_packet_desc; } return 0; } static int uhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags) { int ret; struct uhci_hcd *uhci = hcd_to_uhci(hcd); unsigned long flags; struct urb_priv *urbp; struct uhci_qh *qh; spin_lock_irqsave(&uhci->lock, flags); ret = usb_hcd_link_urb_to_ep(hcd, urb); if (ret) goto done_not_linked; ret = -ENOMEM; urbp = uhci_alloc_urb_priv(uhci, urb); if (!urbp) goto done; if (urb->ep->hcpriv) qh = urb->ep->hcpriv; else { qh = uhci_alloc_qh(uhci, urb->dev, urb->ep); if (!qh) goto err_no_qh; } urbp->qh = qh; switch (qh->type) { case USB_ENDPOINT_XFER_CONTROL: ret = uhci_submit_control(uhci, urb, qh); break; case USB_ENDPOINT_XFER_BULK: ret = uhci_submit_bulk(uhci, urb, qh); break; case USB_ENDPOINT_XFER_INT: ret = uhci_submit_interrupt(uhci, urb, qh); break; case USB_ENDPOINT_XFER_ISOC: urb->error_count = 0; ret = uhci_submit_isochronous(uhci, urb, qh); break; } if (ret != 0) goto err_submit_failed; /* Add this URB to the QH */ urbp->qh = qh; list_add_tail(&urbp->node, &qh->queue); /* If the new URB is the first and only one on this QH then either * the QH is new and idle or else it's unlinked and waiting to * become idle, so we can activate it right away. But only if the * queue isn't stopped. */ if (qh->queue.next == &urbp->node && !qh->is_stopped) { uhci_activate_qh(uhci, qh); uhci_urbp_wants_fsbr(uhci, urbp); } goto done; err_submit_failed: if (qh->state == QH_STATE_IDLE) uhci_make_qh_idle(uhci, qh); /* Reclaim unused QH */ err_no_qh: uhci_free_urb_priv(uhci, urbp); done: if (ret) usb_hcd_unlink_urb_from_ep(hcd, urb); done_not_linked: spin_unlock_irqrestore(&uhci->lock, flags); return ret; } static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) { struct uhci_hcd *uhci = hcd_to_uhci(hcd); unsigned long flags; struct uhci_qh *qh; int rc; spin_lock_irqsave(&uhci->lock, flags); rc = usb_hcd_check_unlink_urb(hcd, urb, status); if (rc) goto done; qh = ((struct urb_priv *) urb->hcpriv)->qh; /* Remove Isochronous TDs from the frame list ASAP */ if (qh->type == USB_ENDPOINT_XFER_ISOC) { uhci_unlink_isochronous_tds(uhci, urb); mb(); /* If the URB has already started, update the QH unlink time */ uhci_get_current_frame_number(uhci); if (uhci_frame_before_eq(urb->start_frame, uhci->frame_number)) qh->unlink_frame = uhci->frame_number; } uhci_unlink_qh(uhci, qh); done: spin_unlock_irqrestore(&uhci->lock, flags); return rc; } /* * Finish unlinking an URB and give it back */ static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh, struct urb *urb, int status) __releases(uhci->lock) __acquires(uhci->lock) { struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv; if (qh->type == USB_ENDPOINT_XFER_CONTROL) { /* urb->actual_length < 0 means the setup transaction didn't * complete successfully. Either it failed or the URB was * unlinked first. Regardless, don't confuse people with a * negative length. */ urb->actual_length = max(urb->actual_length, 0); } /* When giving back the first URB in an Isochronous queue, * reinitialize the QH's iso-related members for the next URB. */ else if (qh->type == USB_ENDPOINT_XFER_ISOC && urbp->node.prev == &qh->queue && urbp->node.next != &qh->queue) { struct urb *nurb = list_entry(urbp->node.next, struct urb_priv, node)->urb; qh->iso_packet_desc = &nurb->iso_frame_desc[0]; qh->iso_frame = nurb->start_frame; } /* Take the URB off the QH's queue. If the queue is now empty, * this is a perfect time for a toggle fixup. */ list_del_init(&urbp->node); if (list_empty(&qh->queue) && qh->needs_fixup) { usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), usb_pipeout(urb->pipe), qh->initial_toggle); qh->needs_fixup = 0; } uhci_free_urb_priv(uhci, urbp); usb_hcd_unlink_urb_from_ep(uhci_to_hcd(uhci), urb); spin_unlock(&uhci->lock); usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, status); spin_lock(&uhci->lock); /* If the queue is now empty, we can unlink the QH and give up its * reserved bandwidth. */ if (list_empty(&qh->queue)) { uhci_unlink_qh(uhci, qh); if (qh->bandwidth_reserved) uhci_release_bandwidth(uhci, qh); } } /* * Scan the URBs in a QH's queue */ #define QH_FINISHED_UNLINKING(qh) \ (qh->state == QH_STATE_UNLINKING && \ uhci->frame_number + uhci->is_stopped != qh->unlink_frame) static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct urb_priv *urbp; struct urb *urb; int status; while (!list_empty(&qh->queue)) { urbp = list_entry(qh->queue.next, struct urb_priv, node); urb = urbp->urb; if (qh->type == USB_ENDPOINT_XFER_ISOC) status = uhci_result_isochronous(uhci, urb); else status = uhci_result_common(uhci, urb); if (status == -EINPROGRESS) break; /* Dequeued but completed URBs can't be given back unless * the QH is stopped or has finished unlinking. */ if (urb->unlinked) { if (QH_FINISHED_UNLINKING(qh)) qh->is_stopped = 1; else if (!qh->is_stopped) return; } uhci_giveback_urb(uhci, qh, urb, status); if (status < 0) break; } /* If the QH is neither stopped nor finished unlinking (normal case), * our work here is done. */ if (QH_FINISHED_UNLINKING(qh)) qh->is_stopped = 1; else if (!qh->is_stopped) return; /* Otherwise give back each of the dequeued URBs */ restart: list_for_each_entry(urbp, &qh->queue, node) { urb = urbp->urb; if (urb->unlinked) { /* Fix up the TD links and save the toggles for * non-Isochronous queues. For Isochronous queues, * test for too-recent dequeues. */ if (!uhci_cleanup_queue(uhci, qh, urb)) { qh->is_stopped = 0; return; } uhci_giveback_urb(uhci, qh, urb, 0); goto restart; } } qh->is_stopped = 0; /* There are no more dequeued URBs. If there are still URBs on the * queue, the QH can now be re-activated. */ if (!list_empty(&qh->queue)) { if (qh->needs_fixup) uhci_fixup_toggles(qh, 0); /* If the first URB on the queue wants FSBR but its time * limit has expired, set the next TD to interrupt on * completion before reactivating the QH. */ urbp = list_entry(qh->queue.next, struct urb_priv, node); if (urbp->fsbr && qh->wait_expired) { struct uhci_td *td = list_entry(urbp->td_list.next, struct uhci_td, list); td->status |= __cpu_to_le32(TD_CTRL_IOC); } uhci_activate_qh(uhci, qh); } /* The queue is empty. The QH can become idle if it is fully * unlinked. */ else if (QH_FINISHED_UNLINKING(qh)) uhci_make_qh_idle(uhci, qh); } /* * Check for queues that have made some forward progress. * Returns 0 if the queue is not Isochronous, is ACTIVE, and * has not advanced since last examined; 1 otherwise. * * Early Intel controllers have a bug which causes qh->element sometimes * not to advance when a TD completes successfully. The queue remains * stuck on the inactive completed TD. We detect such cases and advance * the element pointer by hand. */ static int uhci_advance_check(struct uhci_hcd *uhci, struct uhci_qh *qh) { struct urb_priv *urbp = NULL; struct uhci_td *td; int ret = 1; unsigned status; if (qh->type == USB_ENDPOINT_XFER_ISOC) goto done; /* Treat an UNLINKING queue as though it hasn't advanced. * This is okay because reactivation will treat it as though * it has advanced, and if it is going to become IDLE then * this doesn't matter anyway. Furthermore it's possible * for an UNLINKING queue not to have any URBs at all, or * for its first URB not to have any TDs (if it was dequeued * just as it completed). So it's not easy in any case to * test whether such queues have advanced. */ if (qh->state != QH_STATE_ACTIVE) { urbp = NULL; status = 0; } else { urbp = list_entry(qh->queue.next, struct urb_priv, node); td = list_entry(urbp->td_list.next, struct uhci_td, list); status = td_status(td); if (!(status & TD_CTRL_ACTIVE)) { /* We're okay, the queue has advanced */ qh->wait_expired = 0; qh->advance_jiffies = jiffies; goto done; } ret = 0; } /* The queue hasn't advanced; check for timeout */ if (qh->wait_expired) goto done; if (time_after(jiffies, qh->advance_jiffies + QH_WAIT_TIMEOUT)) { /* Detect the Intel bug and work around it */ if (qh->post_td && qh_element(qh) == LINK_TO_TD(qh->post_td)) { qh->element = qh->post_td->link; qh->advance_jiffies = jiffies; ret = 1; goto done; } qh->wait_expired = 1; /* If the current URB wants FSBR, unlink it temporarily * so that we can safely set the next TD to interrupt on * completion. That way we'll know as soon as the queue * starts moving again. */ if (urbp && urbp->fsbr && !(status & TD_CTRL_IOC)) uhci_unlink_qh(uhci, qh); } else { /* Unmoving but not-yet-expired queues keep FSBR alive */ if (urbp) uhci_urbp_wants_fsbr(uhci, urbp); } done: return ret; } /* * Process events in the schedule, but only in one thread at a time */ static void uhci_scan_schedule(struct uhci_hcd *uhci) { int i; struct uhci_qh *qh; /* Don't allow re-entrant calls */ if (uhci->scan_in_progress) { uhci->need_rescan = 1; return; } uhci->scan_in_progress = 1; rescan: uhci->need_rescan = 0; uhci->fsbr_is_wanted = 0; uhci_clear_next_interrupt(uhci); uhci_get_current_frame_number(uhci); uhci->cur_iso_frame = uhci->frame_number; /* Go through all the QH queues and process the URBs in each one */ for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) { uhci->next_qh = list_entry(uhci->skelqh[i]->node.next, struct uhci_qh, node); while ((qh = uhci->next_qh) != uhci->skelqh[i]) { uhci->next_qh = list_entry(qh->node.next, struct uhci_qh, node); if (uhci_advance_check(uhci, qh)) { uhci_scan_qh(uhci, qh); if (qh->state == QH_STATE_ACTIVE) { uhci_urbp_wants_fsbr(uhci, list_entry(qh->queue.next, struct urb_priv, node)); } } } } uhci->last_iso_frame = uhci->cur_iso_frame; if (uhci->need_rescan) goto rescan; uhci->scan_in_progress = 0; if (uhci->fsbr_is_on && !uhci->fsbr_is_wanted && !uhci->fsbr_expiring) { uhci->fsbr_expiring = 1; mod_timer(&uhci->fsbr_timer, jiffies + FSBR_OFF_DELAY); } if (list_empty(&uhci->skel_unlink_qh->node)) uhci_clear_next_interrupt(uhci); else uhci_set_next_interrupt(uhci); }