On Sun, 13 Sep 2015, Alan Stern wrote: > On Sun, 13 Sep 2015, Roland Weber wrote: > > > I compiled a kernel 3.17(.0) with my additional debug lines... > > and this one does NOT freeze! The output is: > > > > (first unbind) > > ehci-pci 0000:00:1d.0: remove, state 4 > > ehci-pci 0000:00:1d.0: roothub graceful disconnect > > usb usb1: USB disconnect, device number 1 > > ehci-pci 0000:00:1d.0: shutdown urb ffff880072bf4300 ep1in-intr > > usb_remove_hcd: calling stop > > ehci-pci 0000:00:1d.0: stop > > ehci_silence_controller: entry > > ehci_halt: entry > > ehci_halt: after spin_lock_irq > > ehci_halt: about to readl prematurely > > 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. > At some point along the way, can you try adding some printk statements > to ehci_suspend() and ehci_resume() in ehci-hcd.c? I'd like to know if > they get called during the bind/unbind procedure and are responsible > for that 10001 vs. 10000 value. There's one other thing I'd like to see as well. Before doing the unbind, save a copy of /sys/kernel/debug/usb/ehci/0000:00:1d.0/registers. Do this for both types of kernel (one that gets 10000 for the readl value and one that gets 10001). There ought to be some useful information in them. Oh, and also let's see what /sys/bus/pci/devices/0000:00:1d.0/power/control and /sys/bus/pci/devices/0000:00:1d.0/power/runtime_status contain. 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
