Alan Stern wrote: > On Fri, 19 Apr 2013, Joe Rayhawk wrote: >> On Fri, Apr 19, 2013 at 02:18:24PM -0400, Alan Stern wrote: >>> On Fri, 19 Apr 2013, Clemens Ladisch wrote: >>>> Alan Stern wrote: >>>>> + next = uhci->frame_number + 2; >>>>> >>>>> That 2 is the minimum latency, in frames (one frame per ms). >>>> >>>> One frame worked fine with the old driver. What is the reason for >>>> this regression? >>> >>> Perhaps that was a mistake. Joe, you can try changing the 2 above to a >>> 1 to see if it fixes the problem. >> >> Hey, that worked great! Audio's coming through continuously, now. > > This change could be added to the driver, but I would prefer not to. Why do you think it is necessary to have a minimum latency of 2 ms? Again, the old algorithm worked fine. While such short queues are not used by default, they are necessary to get low latencies for real-time audio applications. Keeping this change would keep this regression for quite a few people. > In any case, it would be best What criteria are you using to evaluate the benefit of this? Do you want to reduce the chance of queue underruns? Interrupts? Power usage? > if the usb-audio driver were changed to keep the pipeline length at > least 2 ms at all times. Why is having a queue of two URB with one packet each suddenly not allowed? Regards, Clemens -- 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
