diff options
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 110 |
1 files changed, 57 insertions, 53 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index dd37350170bb..3381319a2b3f 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1413,13 +1413,6 @@ iso_stream_schedule ( goto fail; } - if (stream->depth + span > mod) { - ehci_dbg (ehci, "request %p would overflow (%d+%d>%d)\n", - urb, stream->depth, span, mod); - status = -EFBIG; - goto fail; - } - now = ehci_readl(ehci, &ehci->regs->frame_index) & (mod - 1); /* Typical case: reuse current schedule, stream is still active. @@ -1428,7 +1421,7 @@ iso_stream_schedule ( * slot in the schedule, implicitly assuming URB_ISO_ASAP. */ if (likely (!list_empty (&stream->td_list))) { - start = stream->next_uframe; + u32 excess; /* For high speed devices, allow scheduling within the * isochronous scheduling threshold. For full speed devices @@ -1440,21 +1433,23 @@ iso_stream_schedule ( else next = now; - /* Fell behind (by up to twice the slop amount)? */ - if (((start - next) & (mod - 1)) >= - mod - 2 * SCHEDULE_SLOP) - start += period * DIV_ROUND_UP( - (next - start) & (mod - 1), - period); - - /* Tried to schedule too far into the future? */ - if (unlikely(((start - now) & (mod - 1)) + span - >= mod - 2 * SCHEDULE_SLOP)) { + /* Fell behind (by up to twice the slop amount)? + * We decide based on the time of the last currently-scheduled + * slot, not the time of the next available slot. + */ + excess = (stream->next_uframe - period - next) & (mod - 1); + if (excess >= mod - 2 * SCHEDULE_SLOP) + start = next + excess - mod + period * + DIV_ROUND_UP(mod - excess, period); + else + start = next + excess + period; + if (start - now >= mod) { + ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n", + urb, start - now - period, period, + mod); status = -EFBIG; goto fail; } - stream->next_uframe = start; - goto ready; } /* need to schedule; when's the next (u)frame we could start? @@ -1463,51 +1458,60 @@ iso_stream_schedule ( * can also help high bandwidth if the dma and irq loads don't * jump until after the queue is primed. */ - start = SCHEDULE_SLOP + (now & ~0x07); - start &= mod - 1; - stream->next_uframe = start; - - /* NOTE: assumes URB_ISO_ASAP, to limit complexity/bugs */ - - /* find a uframe slot with enough bandwidth */ - for (; start < (stream->next_uframe + period); start++) { - int enough_space; - - /* check schedule: enough space? */ - if (stream->highspeed) - enough_space = itd_slot_ok (ehci, mod, start, - stream->usecs, period); - else { - if ((start % 8) >= 6) - continue; - enough_space = sitd_slot_ok (ehci, mod, stream, - start, sched, period); + else { + start = SCHEDULE_SLOP + (now & ~0x07); + + /* NOTE: assumes URB_ISO_ASAP, to limit complexity/bugs */ + + /* find a uframe slot with enough bandwidth */ + next = start + period; + for (; start < next; start++) { + + /* check schedule: enough space? */ + if (stream->highspeed) { + if (itd_slot_ok(ehci, mod, start, + stream->usecs, period)) + break; + } else { + if ((start % 8) >= 6) + continue; + if (sitd_slot_ok(ehci, mod, stream, + start, sched, period)) + break; + } } - /* schedule it here if there's enough bandwidth */ - if (enough_space) { - stream->next_uframe = start & (mod - 1); - goto ready; + /* no room in the schedule */ + if (start == next) { + ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n", + urb, now, now + mod); + status = -ENOSPC; + goto fail; } } - /* no room in the schedule */ - ehci_dbg (ehci, "iso %ssched full %p (now %d max %d)\n", - list_empty (&stream->td_list) ? "" : "re", - urb, now, now + mod); - status = -ENOSPC; + /* Tried to schedule too far into the future? */ + if (unlikely(start - now + span - period + >= mod - 2 * SCHEDULE_SLOP)) { + ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n", + urb, start - now, span - period, + mod - 2 * SCHEDULE_SLOP); + status = -EFBIG; + goto fail; + } -fail: - iso_sched_free (stream, sched); - urb->hcpriv = NULL; - return status; + stream->next_uframe = start & (mod - 1); -ready: /* report high speed start in uframes; full speed, in frames */ urb->start_frame = stream->next_uframe; if (!stream->highspeed) urb->start_frame >>= 3; return 0; + + fail: + iso_sched_free(stream, sched); + urb->hcpriv = NULL; + return status; } /*-------------------------------------------------------------------------*/ |