From 84afddd7ac58adad00cb0e50d0af25fcf825668b Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 12 May 2006 11:35:45 -0400 Subject: [PATCH] UHCI: Reimplement FSBR This patch (as683) re-implements Full-Speed Bandwidth Reclamation (FSBR) properly. It keeps track of which endpoint queues have advanced, and when none have advanced for a sufficiently long time, FSBR is turned off. The next TD on each of the non-moving queues is modified to generate an interrupt on completion, so that FSBR can be re-enabled as soon as the hardware starts to make some progress. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/uhci-q.c | 168 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 128 insertions(+), 40 deletions(-) (limited to 'drivers/usb/host/uhci-q.c') diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c index 12af6fb05a3..2be84b3b40f 100644 --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -37,6 +37,46 @@ 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) +{ + uhci->fsbr_is_on = 1; + uhci->skel_term_qh->link = cpu_to_le32( + uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH; +} + +static void uhci_fsbr_off(struct uhci_hcd *uhci) +{ + uhci->fsbr_is_on = 0; + uhci->skel_term_qh->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_qh_wants_fsbr(struct uhci_hcd *uhci, struct uhci_qh *qh) +{ + struct urb_priv *urbp = + list_entry(qh->queue.next, struct urb_priv, node); + + if (urbp->fsbr) { + uhci->fsbr_jiffies = jiffies; + if (!uhci->fsbr_is_on) + uhci_fsbr_on(uhci); + } +} + + static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci) { dma_addr_t dma_handle; @@ -331,6 +371,10 @@ static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh) qh->element = cpu_to_le32(td->dma_handle); } + /* 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; @@ -445,28 +489,6 @@ static void uhci_free_urb_priv(struct uhci_hcd *uhci, kmem_cache_free(uhci_up_cachep, urbp); } -static void uhci_inc_fsbr(struct uhci_hcd *uhci, struct urb *urb) -{ - struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv; - - if ((!(urb->transfer_flags & URB_NO_FSBR)) && !urbp->fsbr) { - urbp->fsbr = 1; - if (!uhci->fsbr++ && !uhci->fsbrtimeout) - uhci->skel_term_qh->link = cpu_to_le32(uhci->skel_fs_control_qh->dma_handle) | UHCI_PTR_QH; - } -} - -static void uhci_dec_fsbr(struct uhci_hcd *uhci, struct urb *urb) -{ - struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv; - - if ((!(urb->transfer_flags & URB_NO_FSBR)) && urbp->fsbr) { - urbp->fsbr = 0; - if (!--uhci->fsbr) - uhci->fsbrtimeout = jiffies + FSBR_DELAY; - } -} - /* * Map status to standard result codes * @@ -613,7 +635,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb, qh->skel = uhci->skel_ls_control_qh; else { qh->skel = uhci->skel_fs_control_qh; - uhci_inc_fsbr(uhci, urb); + uhci_add_fsbr(uhci, urb); } urb->actual_length = -8; /* Account for the SETUP packet */ @@ -756,7 +778,7 @@ static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, qh->skel = uhci->skel_bulk_qh; ret = uhci_submit_common(uhci, urb, qh); if (ret == 0) - uhci_inc_fsbr(uhci, urb); + uhci_add_fsbr(uhci, urb); return ret; } @@ -1075,8 +1097,10 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd, * 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) + if (qh->queue.next == &urbp->node && !qh->is_stopped) { uhci_activate_qh(uhci, qh); + uhci_qh_wants_fsbr(uhci, qh); + } goto done; err_submit_failed: @@ -1135,7 +1159,6 @@ __acquires(uhci->lock) qh->needs_fixup = 0; } - uhci_dec_fsbr(uhci, urb); /* Safe since it checks */ uhci_free_urb_priv(uhci, urbp); switch (qh->type) { @@ -1239,6 +1262,18 @@ restart: 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); } @@ -1248,6 +1283,62 @@ restart: 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. + */ +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) + return ret; + + /* 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; + return ret; + } + ret = 0; + } + + /* The queue hasn't advanced; check for timeout */ + if (!qh->wait_expired && time_after(jiffies, + qh->advance_jiffies + QH_WAIT_TIMEOUT)) { + 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); + } + return ret; +} + /* * Process events in the schedule, but only in one thread at a time */ @@ -1262,7 +1353,7 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs) return; } uhci->scan_in_progress = 1; - rescan: +rescan: uhci->need_rescan = 0; uhci_clear_next_interrupt(uhci); @@ -1275,7 +1366,12 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs) while ((qh = uhci->next_qh) != uhci->skelqh[i]) { uhci->next_qh = list_entry(qh->node.next, struct uhci_qh, node); - uhci_scan_qh(uhci, qh, regs); + + if (uhci_advance_check(uhci, qh)) { + uhci_scan_qh(uhci, qh, regs); + if (qh->state == QH_STATE_ACTIVE) + uhci_qh_wants_fsbr(uhci, qh); + } } } @@ -1283,20 +1379,12 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs) goto rescan; uhci->scan_in_progress = 0; + if (uhci->fsbr_is_on && time_after(jiffies, + uhci->fsbr_jiffies + FSBR_OFF_DELAY)) + uhci_fsbr_off(uhci); + if (list_empty(&uhci->skel_unlink_qh->node)) uhci_clear_next_interrupt(uhci); else uhci_set_next_interrupt(uhci); } - -static void check_fsbr(struct uhci_hcd *uhci) -{ - /* For now, don't scan URBs for FSBR timeouts. - * Add it back in later... */ - - /* 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; - } -} -- cgit v1.2.3-70-g09d2