On Wed, Jun 13, 2012 at 12:12 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > 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? Sorry, I should have been more specific. All the testing (with the exception of the other box below) has been done with the 2.6.38 kernel. I applied your patch by hand to 2.6.38.8. >> 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? Correct. I'll try running the 2.6.38.8 kernel on it. The setup is sufficiently different that it could take me a bit to build and install. I'm not sure what this says though, since case PCI_VENDOR_ID_NVIDIA in ehci-pci.c doesn't clear ehci->need_io_watchdog, so it is using the workaround that made the intel devices work. Austin Schuh -- 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
