[Intel-gfx] [PATCH] drm/i915: Don't try to tear down the stolen drm_mm if it's not there

[Chris Wilson]

On Tue, Jul 02, 2013 at 09:58:45AM +0200, Daniel Vetter wrote:
> On Tue, Jul 02, 2013 at 08:54:30AM +0100, Chris Wilson wrote:
> > On Mon, Jul 01, 2013 at 10:34:30PM +0200, Daniel Vetter wrote:
> > > Every other place properly checks whether we've managed to set
> > > up the stolen allocator at boot-up properly, with the exception
> > > of the cleanup code. Which results in an ugly
> > > 
> > > *ERROR* Memory manager not clean. Delaying takedown
> > > 
> > > at module unload time since the drm_mm isn't initialized at all.
> > > 
> > > v2: While at it check whether the stolen drm_mm is initialized instead
> > > of the more obscure stolen_base == 0 check.
> > > 
> > > v3: Fix up the logic. Also we need to keep the stolen_base check in
> > > i915_gem_object_create_stolen_for_preallocated since that can be
> > > called before stolen memory is fully set up. Spotted by Chris Wilson.
> > 
> > Can you grab a backtrace for stolen_base && !initialized(stolen)? Since
> > preallocated touches the stolen mm, it should be setup by that point.
> 
> I haven't seen it blow up at runtime, but we have special code in
> i915_gem_object_create_stolen_for_preallocated which handles the
> !drm_mm_initialized case. So I've figured we need this. Iirc it's to allow
> us to wrap the vbios framebuffer.

That's a different drm_mm for the ggtt. We still need the stolen mm setup
in order to allocate our memory (as we don't have the same dance to
reconstruct the reserved blocks upon initialisation of stolen).

> Hm, on that notion I wonder whether we should keep the display up while
> doing a module reload - it would be a neat exercise for all that fastboot
> state reconstruction code. Especially the fb reconstruction code would get
> much more pacing than what it gets now (since grub tends to leave the
> display in VGA mode so often ...).

Yes.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre