Re: panic: locking xyz against myself (linux DRM?!)

[Timo Buhrmester <fstd.lkml%gmail.com@localhost>]

> I've been offering the attached patch to try to debug the source of
> the problem before the symptom you described happens.  I haven't
> gotten any diagnostics back from anyone yet.  If you can, please try
> it out and let me know.
I believe we're already discussing this on IRC, but for the record, with your patch and LOCKDEBUG I get:

panic: kernel diagnostic assertion "((mutex->wwm_state != WW_OWNED) || (mutex->wwm_u.owner != curlwp))" failed: file "/usr/src/sys/external/bsd/drm2/linux/linux_ww_mutex.c", line 760 locking 0xfffffe8084178220 against myself: 0xfffffe811d915700
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff8028be15 cs 8 rflags 246 cr2 7f7ff2e62000 ilevel 8 rsp fffffe804175dad8
curlwp 0xfffffe811d915700 pid 2288.1 lowest kstack 0xfffffe804175a2c0
Stopped in pid 2288.1 (Xorg) at netbsd:breakpoint+0x5:  leave
db{0}> bt
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x13c
kern_assert() at netbsd:kern_assert+0x4f
linux_ww_mutex_trylock() at netbsd:linux_ww_mutex_trylock+0xed
ttm_bo_uvm_fault() at netbsd:ttm_bo_uvm_fault+0x69
radeon_ttm_fault() at netbsd:radeon_ttm_fault+0x6a
uvm_fault_internal() at netbsd:uvm_fault_internal+0x828
trap() at netbsd:trap+0x249
--- trap (number 6) ---
7f7ff002e4ed:
db{0}>


Cheers