On Fri, 2 Aug 2013, James Stone wrote: > > OK - here's a trace with all patches applied. It didn't occur when the > > webcam was re-plugged this time.. This one happened when opening the > > trace file while it was being written to. I hope this is OK? It seems > > to be a fairly consistent way to get the audio to hang up, but I'm not > > sure it is such a "natural" way to induce the bug tho? > > > > Another trace - this time occurring when plugging in a usb game > controller.. so I guess the webcam isn't the culprit! Traces that show a delay of less than 1 ms aren't very interesting, in general. However, they do show that the scheduling code in ehci-hcd takes longer than it should (although it probably runs more quickly when tracing isn't turned on). I've known for a long time that the scheduler in ehci-hcd needs to be rewritten completely. It's a big job, so I've been avoiding it... Some event that causes a whole bunch of those new "underrun" messages in the system log would be worth seeing. Alan Stern -- 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
