Panic on drm-devel v5.5.19.g20210909

From: Pete Wright via freebsd-x11 <freebsd-x11_at_freebsd.org>
Date: Fri, 10 Sep 2021 23:53:48 UTC 
hello,
i got the following panic after upgrading my current laptop to 
drm-devel-v5.5.19.g20210909 (3df6598adf625a18a7c762b2d48b4c3dd7925838):

panic: acquiring blockable sleep lock with spinlock or critical section 
held (sleep mutex) linux_wq_exec @ 
/usr/home/pete/git/freebsd/sys/compat/linuxkpi/common/src/linux_work.c:105
cpuid = 5
time = 1631315668
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe011d086060
vpanic() at vpanic+0x187/frame 0xfffffe011d0860c0
panic() at panic+0x43/frame 0xfffffe011d086120
witness_checkorder() at witness_checkorder+0xe78/frame 0xfffffe011d0862f0
__mtx_lock_flags() at __mtx_lock_flags+0x94/frame 0xfffffe011d086340
linux_queue_work_on() at linux_queue_work_on+0x9a/frame 0xfffffe011d086380
dma_fence_signal() at dma_fence_signal+0xc0/frame 0xfffffe011d0863d0
dma_resv_add_shared_fence() at dma_resv_add_shared_fence+0x96/frame 
0xfffffe011d086420
i915_vma_move_to_active() at i915_vma_move_to_active+0x7e/frame 
0xfffffe011d086460
i915_gem_do_execbuffer() at i915_gem_do_execbuffer+0x13d7/frame 
0xfffffe011d086670
i915_gem_execbuffer2_ioctl() at i915_gem_execbuffer2_ioctl+0x195/frame 
0xfffffe011d0866e0
drm_ioctl_kernel() at drm_ioctl_kernel+0x72/frame 0xfffffe011d086730
drm_ioctl() at drm_ioctl+0x2bf/frame 0xfffffe011d086820
linux_file_ioctl() at linux_file_ioctl+0x297/frame 0xfffffe011d086880
kern_ioctl() at kern_ioctl+0x202/frame 0xfffffe011d0868f0
sys_ioctl() at sys_ioctl+0x124/frame 0xfffffe011d0869c0
amd64_syscall() at amd64_syscall+0x12e/frame 0xfffffe011d086af0
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe011d086af0
--- syscall (54, FreeBSD ELF64, sys_ioctl), rip = 0x80f1ae3ca, rsp = 
0x7fffffffc8d8, rbp = 0x7fffffffc970 ---
KDB: enter: panic


I have a core and and additional info if that'll help debug this issue.  
it happened three times while doing normal web+shell work.  i've 
reverted to the commit previous this one and it looks like the system no 
longer panic's.

-pete

-- 
Pete Wright
pete@nomadlogic.org
@nomadlogicLA