On 16 November 2015 at 23:22, Alan Stern <st...@rowland.harvard.edu> wrote: > On Mon, 16 Nov 2015, Daniel J Blueman wrote: > >> Tuning USB suspend [1] in 4.3 on a Dell XPS 15 9553 (Skylake), I see a >> kworker thread spinning in rpm_suspend [2]. >> >> What is the most useful debug to get here beyond the immediate [3]? > > You can try doing: > > echo 'module usbcore =p' >/sys/kernel/debug/dynamic_debug/control
kworker and ksoftirqd spinning occurs when I echo 'auto' to all the USB control entries. Using Alan's excellent tip, we see this being logged repeatedly at a high rate: [ 353.245180] usb usb1-port4: status 0107 change 0000 [ 353.245194] usb usb1-port12: status 0507 change 0000 [ 353.245202] hub 1-0:1.0: state 7 ports 16 chg 0000 evt 0000 [ 353.245203] hub 1-0:1.0: hub_suspend [ 353.245205] usb usb1: bus auto-suspend, wakeup 1 [ 353.245206] usb usb1: bus suspend fail, err -16 [ 353.245207] hub 1-0:1.0: hub_resume ... So, EBUSY. Both the webcam is not open, and the bluetooth interface [1] is rfkill'd; the situation occurs even if I unload all related modules. What further debug would be useful? Thanks! Daniel -- [1] Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 0a5c:6410 Broadcom Corp. Bus 001 Device 003: ID 1bcf:2b95 Sunplus Innovation Technology Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
