I applied below patch in my linux-3.8.13. https://lkml.org/lkml/2013/8/18/203 <"[ 35/45] USB: EHCI: accept very late isochronous URBs">
After then, I got a lot of warning messages like as below. [ 133.760978] ehci 100f0000.ehci: iso underrun e07c1840 (3375+0 < 5472) [ 133.760999] ehci 100f0000.ehci: iso underrun e07c1d80 (3383+0 < 5473) [ 133.761023] ehci 100f0000.ehci: iso underrun e07c1e40 (3391+0 < 5473) [ 133.761046] ehci 100f0000.ehci: iso underrun e07c16c0 (3399+0 < 5473) [ 133.761067] ehci 100f0000.ehci: iso underrun e07c10c0 (3407+0 < 5473) [ 133.761088] ehci 100f0000.ehci: iso underrun e07c1f00 (3415+0 < 5473) [ 133.761110] ehci 100f0000.ehci: iso underrun e07c1000 (3423+0 < 5474) [ 133.761132] ehci 100f0000.ehci: iso underrun e07c1900 (3431+0 < 5474) [ 133.761152] ehci 100f0000.ehci: iso underrun e07c1840 (3439+0 < 5474) [ 133.761172] ehci 100f0000.ehci: iso underrun e07c1d80 (3447+0 < 5474) [ 133.761191] ehci 100f0000.ehci: iso underrun e07c1e40 (3455+0 < 5474) [ 133.761211] ehci 100f0000.ehci: iso underrun e07c16c0 (3463+0 < 5474) [ 133.761233] ehci 100f0000.ehci: iso underrun e07c10c0 (3471+0 < 5475) [ 133.761253] ehci 100f0000.ehci: iso underrun e07c1f00 (3479+0 < 5475) [ 133.761271] ehci 100f0000.ehci: iso underrun e07c1000 (3487+0 < 5475) [ 133.761292] ehci 100f0000.ehci: iso underrun e07c1900 (3495+0 < 5475) [ 133.761312] ehci 100f0000.ehci: iso underrun e07c1840 (3503+0 < 5475) [ 133.761331] ehci 100f0000.ehci: iso underrun e07c1d80 (3511+0 < 5475) ....... When audio process was dead, my webcam does not recognize about process dead. So webcam continuously send audio data to my system. At that time, continuously above warning messages were occured, and my system was slowed. As I knew, this message is in irq routine. If system print a lot of messages, system will be slowed. How can I solve this problem? Thanks Minsu -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1191603 Title: raring-updates: regression: 3.8.0-24.35 causes sporadic failure of USB audio devices To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1191603/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
