[Intel-gfx] [PATCH] drm/i915: check if execlist_port is empty before using its content

[Du, Changbin]

> On Fri, Dec 23, 2016 at 01:46:36PM +0800, changbin.du at intel.com wrote:
> > From: "Du, Changbin" <changbin.du at intel.com>
> >
> > This patch fix a crash in function reset_common_ring. In this case,
> > the port[0].request is null when reset the render ring, so a null
> > dereference exception is raised. We need to check execlist_port status
> > first.
> 
> No. The root cause is whatever got you into the illegal condition in the
> first place.
> -Chris
> 
Thanks, I will restudy the code after process my current job. Since this happen
on gvt guest, so this may related to gvt emulation.

> --
> Chris Wilson, Intel Open Source Technology Centre