Re: kern/49022: Locking issues in interaction of TTY and USB subsystems (exposed with uhso(4))

[Nick Hudson <skrll%netbsd.org@localhost>]

On 07/19/14 19:30, n54%gmx.com@localhost wrote:
> #3 0xffffffff80770501 in lockdebug_abort1 (ld=0xffff800005989658, s=6,
> func=0xffffffff80b40220 "lockdebug_barrier",
> msg=0xffffffff80bf98de "spin lock held", dopanic=true)
> at ../../../../kern/subr_lockdebug.c:783
> #4 0xffffffff80539b1c in mutex_vector_enter (mtx=0xfffffe8006d1c010)
> at ../../../../kern/kern_mutex.c:487
> #5 0xffffffff802aacc2 in ehci_device_bulk_transfer (xfer=0xfffffe8006d69a10)
> at ../../../../dev/usb/ehci.c:3547
> #6 0xffffffff808473dc in usbd_transfer (xfer=0xfffffe8006d69a10)
> at ../../../../dev/usb/usbdi.c:300
> #7 0xffffffff80814fe2 in uhso_bulk_write (hp=0xfffffe80be282288)
> at ../../../../dev/usb/uhso.c:1187
> #8 0xffffffff80816bc6 in uhso_tty_start (tp=0xfffffe80be28c6c8)
> at ../../../../dev/usb/uhso.c:1820
> #9 0xffffffff807cb840 in ttstart (tp=0xfffffe80be28c6c8)
> at ../../../../kern/tty.c:1680
> #10 ttwrite (tp=0xfffffe80be28c6c8, uio=0xfffffe8007246de0,
> flag=<optimized out>) at ../../../../kern/tty.c:2196

tty_lock is held here...

   2196         ttstart(tp);
   2197         mutex_spin_exit(&tty_lock);

http://nxr.netbsd.org/xref/src/sys/kern/tty.c#2196

Nick