Re: RPI-B 11.0-ALPHA3 r301815 panic ["when connecting via WiFi"]

On Fri, 2016-06-17 at 07:52 -0700, Adrian Chadd wrote:
> Just disable 11n for now. ifconfig wlan0 -ht (and reassociate.)
> 
> See if it's that.
> 
> 
> 
> -adrian
> 

You can see from the crash info that it's an alignment fault:

  r6 =c21a4876
  ldmib   r6,{r1-r2}

An ldm instruction requires 4-byte alignment.  Now the question is why
undefining __NO_STRICT_ALIGNMENT didn't fix the problem.  Maybe the
wifi code doesn't use __NO_STRICT_ALIGNMENT the same way other network
drivers do?

Unfortunately the pasted info lists the nearby symbol as $a.17+0x38,
which doesn't help find the actual code.  A stack backtrace might help.

-- Ian

> 
> On 17 June 2016 at 04:19, Keith White <kwhite_at_site.uottawa.ca> wrote:
> > On Thu, 16 Jun 2016, Keith White wrote:
> > 
> > > On Wed, 15 Jun 2016, Mark Millard wrote:
> > > 
> > > > https://lists.freebsd.org/pipermail/freebsd-current/2016-June/0
> > > > 61904.html
> > > > reports an RPI-B alignment fault for -r301815 (the snapshot)
> > > > "when
> > > > connecting via WiFi".
> > > > 
> > > > -r301872 (
> > > > https://lists.freebsd.org/pipermail/svn-src-head/2016-June/0883
> > > > 39.html ) has
> > > > a fix for networking vs. alignment handling for armv6 contexts
> > > > that might be
> > > > needed. Quoting:
> > > > 
> > > > > Author: ian
> > > > > Date: Mon Jun 13 16:48:27 2016
> > > > > New Revision: 301872
> > > > > URL:
> > > > > https://svnweb.freebsd.org/changeset/base/301872
> > > > 
> > > > ...
> > > 
> > > 
> > > Thanks for pointing this out!  I'll see if a (complete) rebuild
> > > at
> > > that rev fixes the problem.
> > > 
> > 
> > Tried that.  I still get a panic.
> > 
> > I cross built on an amd64 at r301840, I'll try upgrading that
> > machine too.
> > 
> > In the meantime, other suggestions?
> > 
> > FreeBSD 11.0-ALPHA3 #0 r301872: Thu Jun 16 21:11:44 EDT 2016
> >     kwhite_at_freebsd11:/usr/obj/arm.armv6/usr/src/sys/RPI-B arm
> > FreeBSD clang version 3.8.0 (tags/RELEASE_380/final 262564) (based
> > on LLVM
> > 3.8.0)
> > VT: init without driver.
> > ...
> > Starting devd.
> > urtwn0: <vendor 0x0bda product 0x8176, class 0/0, rev 2.00/2.00,
> > addr 4> on
> > usbus0
> > urtwn0: MAC/BB RTL8188CUS, RF 6052 1T1R
> > urtwn0: enabling 11n
> > wlan0: Ethernet address: 00:13:ef:74:07:a8
> > Created wlan(4) interfaces: wlan0.
> > ...
> > 
> > [ nc rpi-b 22 ]
> > Fatal kernel mode data abort: 'Alignment Fault' on read
> > trapframe: 0xc18f28c0
> > FSR=00000001, FAR=c21a487a, spsr=60000013
> > r0 =c07a6548, r1 =00000004, r2 =c0605338, r3 =000007b6
> > r4 =c18f2a28, r5 =c18f2b40, r6 =c21a4876, r7 =c1ccd240
> > r8 =c1ccd240, r9 =c21a4Stopped at      $a.17+0x38:     ldmib   r6,
> > {r1-r2}
> > db>
> > 
> > 
> > ...keith
> > _______________________________________________
> > freebsd-current_at_freebsd.org mailing list
> > https://lists.freebsd.org/mailman/listinfo/freebsd-current
> > To unsubscribe, send any mail to "
> > freebsd-current-unsubscribe_at_freebsd.org"
> _______________________________________________
> freebsd-current_at_freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "
> freebsd-current-unsubscribe_at_freebsd.org"