> Hello, > > On 21.2.2014 15:09, Michal Šmucr wrote: > > > > I tried both patches separately on 3.14-rc3 and second patch alone > > helped here. I wasn't able to reproduce babble interrupt anymore, no > > matter, what i did with my hub and USB peripherals. Great! > > > > Unfortunately i found another appearance of Babble and this time without any > workaround. > Recently I tested HiFace USB audio interface > (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/sound/usb/hi > face), > mainly because it using bulk transfers instead of isochronous ones and i was > curious, if it will be also affected by high CPU utilization issue, which i reported > in my other posts. > After connection to Beaglebone it seems to be correctly enumerated (albeit > with one warning about its reported standard violating maxpacket length, but it Probably this would be cause for babble? Did you observed bus traces, whether 1024 bytes seen or any break in the packet. > shouldn't be lethal). Then after initiating of audio playback, Babble interrupt > occurs and this is the end. > Force cancellation of playback emits couple of warnings in dmesg, but this is > probably sign of unfinished urbs. This clearly shows that babble would have occurred in b/w packet transfer, this has caused controller to stop and further transmission is halted by endpoint. Only way to recover this is to restart the controller, use the babble workaround patch to restart the controller. > > Just for completeness, audio interface works well on Intel NUC board with same > kernel version. > --Ravi Babu ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
