Re: crash with latest audio changes

[christos%zoulas.com@localhost (Christos Zoulas)]

On Dec 16,  5:51pm, dtyson%anduin.org.uk@localhost (Dave Tyson) wrote:
-- Subject: Re: crash with latest audio changes

| On Friday 16 Dec 2016 16:13:35 Christos Zoulas wrote:
| > In article <35284500.X7LH1kdvpI%cruncher.anduin.org.uk@localhost>,
| > 
| > Dave Tyson  <dtyson%anduin.org.uk@localhost> wrote:
| > >I updated a DELL system from 7.99.39 (Oct 13th) to the latest current (Dec
| > >16th). When I bring up KDE the newer kernel panics in the audio code, works
| > >fine with older kernel. I guess this relates to the recent in-kernel mixer
| > >changes.
| > 
| > I just committed something that should help with this. Can you try again
| > and also look in dmesg about where the attach for audio fails?
| > 
| > thanks,
| > christos
| 
| OK, CVS'ed up and rebuilt a new kernel. This crashes in the same way and the 
| backtrace looked identical so I just checked that I hadn't loaded the earlier 
| kernel. ident showed it had audio.c 1.280 Phew! 
| 
| uvm_fault(0xfffffe811cc93730, 0x0, 1) -> e
| fatal page fault in supervisor mode
| trap type 6 code 0 rip ffffffff80641d0f cs 8 rflags 10246 cr2 71a ilevel 0 rsp 
| fffffe8040445c00
| curlwp 0xfffffe8118d8d1e0 pid 481.1 lowest kstack 0xfffffe80404422c0
| panic: trap
| cpu1: Begin traceback...
| vpanic() at netbsd:vpanic+0x140
| snprintf() at netbsd:snprintf
| trap() at netbsd:trap+0xc76
| --- trap (number 6) ---
| audio_get_port() at netbsd:audio_get_port+0x7e
| audioioctl() at netbsd:audioioctl+0x84
| VOP_IOCTL() at netbsd:VOP_IOCTL+0x3b
| vn_ioctl() at netbsd:vn_ioctl+0xa6
| sys_ioctl() at netbsd:sys_ioctl+0x101
| syscall() at netbsd:syscall+0x1df
| --- syscall (number 54) ---
| 7aefaaae933a:
| cpu1: End traceback...
| 

audio_get_port+0x7e is this line:
	        return sc->hw_if->get_port(sc->hw_hdl, mc);

I don't see how we can get there with sc->hw_if being NULL..
Add some printfs to see what's NULL...

christos