diff options
Diffstat (limited to 'drivers/usb/host/ehci-sched.c')
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 2e829fae6482..a60679cbbf85 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1475,30 +1475,36 @@ iso_stream_schedule ( * jump until after the queue is primed. */ else { + int done = 0; 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++) { - + /* find a uframe slot with enough bandwidth. + * Early uframes are more precious because full-speed + * iso IN transfers can't use late uframes, + * and therefore they should be allocated last. + */ + next = start; + start += period; + do { + start--; /* check schedule: enough space? */ if (stream->highspeed) { if (itd_slot_ok(ehci, mod, start, stream->usecs, period)) - break; + done = 1; } else { if ((start % 8) >= 6) continue; if (sitd_slot_ok(ehci, mod, stream, start, sched, period)) - break; + done = 1; } - } + } while (start > next && !done); /* no room in the schedule */ - if (start == next) { + if (!done) { ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n", urb, now, now + mod); status = -ENOSPC; |