The EHCI driver does some bounds checking when it's scheduling an iTD for an active endpoint. It sets the local variable start to stream->next_uframe and moves that variable further in the schedule if necessary. However, the driver fails to do anything with start before jumping to the ready label and setting the URB's starting frame to stream->next_uframe. Alan Stern confirms the EHCI driver should set stream->next_uframe to start before jumping. Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> CC: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> --- I tested this patch with a FS webcam behind a HS hub. It doesn't cause any problems, and the number of isoc packets with errors is the same with or without the patch. You would probably only see the effect of this code if the system was under heavy load, correct? drivers/usb/host/ehci-sched.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 3ea0593..3efa59b 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1425,6 +1425,7 @@ iso_stream_schedule ( status = -EFBIG; goto fail; } + stream->next_uframe = start; goto ready; } -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
