On Tue, 6 Oct 2009, Sarah Sharp wrote: > 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? Fairly heavy load, yes. Interrupt delivery and processing would have to be delayed by at least 125 us. Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> -- 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
