On Wed, Dec 25, 2013 at 09:51:28PM -0500, Alan Stern wrote: > Okay, now we know that usb_enable_interface takes a long time. That > routine does nothing but call usb_enable_endpoint, which does nothing > but call usb_hcd_reset_endpoint, which calls the xhci_endpoint_reset > routine. > > So we have traced the problem into xhci-hcd. You could trace it > farther down if you want, but at this point it probably would be more > productive to see what Sarah has to say. She may know about some new > changes that are not yet available in the development kernel. I suspect the patch I asked Matthias and Holger to apply [1] has some issues, and it's entirely possible that there's deadlocks. One other tester (Michal) confirms it fixes his issue with a Samsung scanner, but the patch leads to list corruption in some xHCI structures: https://bugzilla.kernel.org/show_bug.cgi?id=47421 In any case, all three testers (Matthias, Holger, and Michal) confirm the patch fixes the underlying issue. So we just need to get the remaining race conditions and locking issues fixed up. Xenia, would you mind if Dan or I finished your patch? I know you don't have much time for xHCI work since you started your new job. Sarah Sharp [1] http://marc.info/?l=linux-usb&m=138116117104619&w=2 -- 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
