[Intel-gfx] still experiencing oops connecting Laptop to docking Station

[Daniel Vetter]

On Thu, May 21, 2015 at 04:30:34PM +0200, Nicolas Kalkhof wrote:
> Hi Daniel,
>  
> > Ah, Chris hunch against my claim that this is impossible was spot-on. Can
> > you please try the below hack please and grab dmesg? Hopefully the kernel
> > won't die any more at least.
> 
> Unfortunately the patch doesn't keep my machine from crashing.
> 
> image of stack trace: http://imgur.com/CV5ho1B
> dmesg: http://pastebin.com/T69SPT3g
> 
> it seems that the problem now occurs in drm_atomic_get_connector_state.

Hm something seems to be deeply wrong here. And the oops you've captured
still doesn't include the debug messages before things go boom. Can you
please replace the WARN_ON in my previous patch with a BUG_ON? That should
stop the machine at least and hopefully prevents it all from going boom.

And please play around with dmesg -n to get these debug messages to the
console. I really need them to figure out what's going wrong here.
-Daniel

> 
> (gdb) list *drm_atomic_get_connector_state+0x40
> 0xff0 is in drm_atomic_get_connector_state (drivers/gpu/drm/drm_atomic.c:652).
> 647              *
> 648              * Note that we only grab the indexes once we have the right lock to
> 649              * prevent hotplug/unplugging of connectors. So removal is no problem,
> 650              * at most the array is a bit too large.
> 651              */
> 652             if (index >= state->num_connector) {
> 653                     DRM_DEBUG_ATOMIC("Hot-added connector would overflow state array, restarting\n");
> 654                     return ERR_PTR(-EAGAIN);
> 655             }
> 656
> (gdb)   
> 
> HTH
> Nic

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch