panic: sleeping thread. Possibly related to drm and swapping.

Just recieved this panic.

I am using drm-legacy-kmod-g20200306 on a Dell Latitude D530 laptop.
The panic occurred as I was starting libreoffice.  Suggestions?

mobile dumped core - see /var/crash/vmcore.2

Wed Apr 15 09:22:07 PDT 2020

FreeBSD mobile 13.0-CURRENT FreeBSD 13.0-CURRENT #2 r359179M: Sat Mar 21 13:46:12 PDT 2020     root_at_mobile:/usr/obj/usr/src/i386.i386/sys/MOBILE  i386

panic: sleeping thread

Reading symbols from /boot/kernel/kernel...
Reading symbols from /usr/lib/debug//boot/kernel/kernel.debug...

Unread portion of the kernel message buffer:
Sleeping thread (tid 100154, pid 1072) owns a non-sleepable lock
KDB: stack backtrace of thread 100154:
sched_switch(22209e00,104) at sched_switch+0x173/frame 0x220e04c8
mi_switch(104) at mi_switch+0x13e/frame 0x220e0500
sleepq_switch(2239ecac,ffffe8e0,2239ecac,2239ec2c,220e0574,...) at sleepq_switch+0xe3/frame 0x220e0518
sleepq_timedwait(2239ecac,50) at sleepq_timedwait+0x2a/frame 0x220e0540
_sleep(2239ecac,2239ec2c,50,fcc13e,ffffe8e0,13,0,0,100) at _sleep+0x176/frame 0x220e0574
swap_pager_getpages_locked(1,0,0) at swap_pager_getpages_locked+0x6b5/frame 0x220e05dc
swap_pager_getpages(2239ec2c,220e0640,1,0,0) at swap_pager_getpages+0x40/frame 0x220e05fc
vm_pager_get_pages(2239ec2c,220e0640,1,0,0,...) at vm_pager_get_pages+0x26/frame 0x220e0624
i915_gem_wire_page(0,220e0677,2239ec2c,0,2239ec3c,...) at i915_gem_wire_page+0x6b/frame 0x220e0650
i915_gem_object_get_pages_gtt(8af4700,2189a000,102,22569800,1000,...) at i915_gem_object_get_pages_gtt+0xb0/frame 0x220e0684
i915_gem_object_pin(8af4700,0,0,0,22779000,...) at i915_gem_object_pin+0x3ca/frame 0x220e06c0
i915_gem_execbuffer_reserve_object(5f,4f2a700,8af2b5c,18e59a5c,22779110,...) at i915_gem_execbuffer_reserve_object+0x64/frame 0x220e06e8
i915_gem_execbuffer_reserve(22209e00,22779110,20,24da9600,0,...) at i915_gem_execbuffer_reserve+0x1e8/frame 0x220e0720
i915_gem_do_execbuffer(220e0b70,28f2a000,11,fffffff3,22569800,...) at i915_gem_do_execbuffer+0x845/frame 0x220e09a8
i915_gem_execbuffer2(22569800,220e0b70,22505200,69,21ca3410,...) at i915_gem_execbuffer2+0xf6/frame 0x220e09c8
drm_ioctl(1847fa00,c0406469,220e0b70,7,22209e00) at drm_ioctl+0x31b/frame 0x220e09f4
devfs_ioctl(220e0a60) at devfs_ioctl+0x99/frame 0x220e0a2c
VOP_IOCTL_APV(10c0614,220e0a60) at VOP_IOCTL_APV+0x18/frame 0x220e0a40
vn_ioctl(218a3070,c0406469,220e0b70,22291d00,22209e00) at vn_ioctl+0x13a/frame 0x220e0af0
devfs_ioctl_f(218a3070,c0406469,220e0b70,22291d00,22209e00) at devfs_ioctl_f+0x2c/frame 0x220e0b18
kern_ioctl(22209e00,a,c0406469,220e0b70) at kern_ioctl+0x1ea/frame 0x220e0b50
sys_ioctl(22209e00,2220a090,220e0cdc,22209e00,3206,...) at sys_ioctl+0xd4/frame 0x220e0c08
syscall(220e0ce8,3b,3b,3b,ffbfeb90,...) at syscall+0x1fd/frame 0x220e0cdc
Xint0x80_syscall() at 0xffc033f9/frame 0x220e0cdc
--- syscall (54, FreeBSD ELF32, sys_ioctl), eip = 0xffc05f6c, esp = 0xffc07fe8, ebp = 0xffbfeb54 ---
panic: sleeping thread
cpuid = 0
time = 1586967582
KDB: stack backtrace:
db_trace_self_wrapper(aee2f1,1,21935470,1828d8e4,a0f170,...) at db_trace_self_wrapper+0x2a/frame 0x1828d8b8
kdb_backtrace(2,80,22209e00,8a5fa00,c,...) at kdb_backtrace+0x2e/frame 0x1828d918
vpanic(1002aba,1828d954,1828d954,1828d968,c7a399,...) at vpanic+0x11f/frame 0x1828d934
panic(1002aba,c,8a5fa00,17ffe000,8a5fa00,...) at panic+0x14/frame 0x1828d948
propagate_priority(0,246,0,0,22209e00,...) at propagate_priority+0x239/frame 0x1828d968
turnstile_wait(8a5fa00,22209e00,0) at turnstile_wait+0x285/frame 0x1828d984
__rw_wlock_hard(2239ec3c,22209e00) at __rw_wlock_hard+0x40d/frame 0x1828da00
swp_pager_async_iodone(18ef1000,0,157000,ffffffff,18eec000,...) at swp_pager_async_iodone+0x294/frame 0x1828da24
bufdone(18ef1000) at bufdone+0x60/frame 0x1828da64
swapgeom_done(18eec000) at swapgeom_done+0x44/frame 0x1828da7c
g_io_deliver(18eec000,0) at g_io_deliver+0x1e7/frame 0x1828dab8
g_std_done(2eae4b58) at g_std_done+0x78/frame 0x1828dacc
g_io_deliver(2eae4b58,0) at g_io_deliver+0x1e7/frame 0x1828db08
g_std_done(246ee108) at g_std_done+0x78/frame 0x1828db1c
g_io_deliver(246ee108,0) at g_io_deliver+0x1e7/frame 0x1828db58
g_disk_done(2ce1fd68,28,18f5e000,0,0,...) at g_disk_done+0x10a/frame 0x1828db8c
adadone(8bfd880,2cddc800) at adadone+0x86e/frame 0x1828dbcc
xpt_done_process(25a51,8ad8e68e,e7c6bed,18058000,0,...) at xpt_done_process+0x3fd/frame 0x1828dbf8
xpt_done_direct(2cddc800) at xpt_done_direct+0x39/frame 0x1828dc1c
ahci_ch_intr_direct(18058000) at ahci_ch_intr_direct+0xe6/frame 0x1828dc48
ahci_intr_one(17fab454) at ahci_intr_one+0x23/frame 0x1828dc5c
ithread_loop(8e23ea0,1828dce8) at ithread_loop+0x1a0/frame 0x1828dcb8
fork_exit(be4b10,8e23ea0,1828dce8,0,0,...) at fork_exit+0x66/frame 0x1828dcd4
fork_trampoline() at 0xffc0340e/frame 0x1828dcd4
--- kthread start
KDB: enter: panic

0x00c1e379 in doadump (textdump=0) at /usr/src/sys/kern/kern_shutdown.c:393
393		savectx(&dumppcb);
(kgdb) #0  0x00c1e379 in doadump (textdump=0)
    at /usr/src/sys/kern/kern_shutdown.c:393
#1  0x009c0a89 in db_fncall_generic (addr=<optimized out>, nargs=0, 
    args=<optimized out>, rv=<optimized out>)
    at /usr/src/sys/ddb/db_command.c:610
#2  db_fncall (dummy1=405329652, dummy2=false, dummy3=145217792, 
    dummy4=0x1828d6f0 "pT\223!\f\327(\030", <incomplete sequence \361\240>)
    at /usr/src/sys/ddb/db_command.c:658
#3  0x009c05c8 in db_command (last_cmdp=<optimized out>, 
    cmd_table=<optimized out>, dopager=1) at /usr/src/sys/ddb/db_command.c:482
#4  0x009c032c in db_command_loop () at /usr/src/sys/ddb/db_command.c:535
#5  0x009c3426 in db_trap (type=3, code=0) at /usr/src/sys/ddb/db_main.c:253
#6  0x00c64c39 in kdb_trap (type=3, code=0, tf=0x1828d8cc)
    at /usr/src/sys/kern/subr_kdb.c:699
#7  0x00f9324a in trap (frame=0x1828d8cc) at /usr/src/sys/i386/i386/trap.c:668
#8  0xffc0319f in ?? ()
#9  0x1828d8cc in ?? ()
#10 0x00000028 in ?? ()
#11 0x00000028 in ?? ()
#12 0x00000100 in ?? ()
#13 0x0101ae42 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(kgdb) 


-- 
Steve