On Tue, 15 Sep 2015, Roland Weber wrote: > Hi Alan, > > > > ehci_halt: premature readl returned 10001 > > > > Note: 10001 instead of 10000, which is what you saw in the other > > kernel. That could be highly relevant. > > Really? And I thought that was the least significant bit... It is the least significant bit in the register, but it is the bit that indicates whether or not the controller is running, which makes it one of the most important. :-) > I had a lucky guess among the 2000+ lines of diff output with > which I started: CONFIG_PM_RUNTIME makes the difference. > If it's on, the kernel can freeze. Aha, good. I was heading in the same general direction. > I'll have to add the debug output you asked for tomorrow, > didn't expect to succeed so soon. > > Should I put the statements into the 3.17 kernel, or should I > try to compile a 4.2 without CONFIG_PM_RUNTIME instead? And > would you like the output of a freezing or non-freezing kernel > first? I'll only be able to try out one tomorrow, the rest > will follow a day or two later. As long as the 4.2 kernel can do what you want, you may as well use it. However, note that CONFIG_PM_RUNTIME doesn't exist any more in 4.2; it is now covered by CONFIG_PM. Assuming things work out as expected, try this: In core/hub.c, remove the calls to usb_enable_autosuspend(hdev) in hub_probe() and leave CONFIG_PM enabled. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
