On Wed, 13 Jun 2012, Austin Schuh wrote: > > A known software bug could also cause interrupts to get lost, although > > I have never observed this. �A patch (for the 3.4 kernel) to fix this > > bug is below; you could try it with ehci->need_io_watchdog set back to > > 0. > > The fix below with ehci->need_io_watchdog set to 0 locks up. Was that using a 3.4 kernel, or are you still back on 2.6.38? > > Are the two computers you tried both SMP systems? > > Both systems are SMP. > > desktop: > 2.6.38.8 #11 SMP Tue Jun 12 18:47:20 PDT 2012 x86_64 GNU/Linux > > laptop: > 2.6.38-15-generic #60~lucid1-Ubuntu SMP Wed May 23 15:04:42 UTC 2012 > x86_64 GNU/Linux > > To add another data point, I ran the code on a machine with > USB Controller: nVidia Corporation MCP79 EHCI USB 2.0 Controller (rev b1) > and kernel > 2.6.32-41-generic #89-Ubuntu SMP Fri Apr 27 22:18:56 UTC 2012 x86_64 GNU/Linux > and it worked. I ran it for over 1000 cycles without issue. You changed two things here: the EHCI vendor and the kernel version. What happens if you change only one a time? 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
