diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 063c630d2467..fb2d0c2f0670 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1483,10 +1483,15 @@ iso_stream_schedule ( /* 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, @@ -1499,7 +1504,7 @@ iso_stream_schedule ( start, sched, period)) break; } - } + } while (start > next); /* no room in the schedule */ if (start == next) { |