[Nouveau] [PATCH] drm/nouveau/bl: Fix oops on driver unbind

[Lukas Wunner]

On Mon, Feb 19, 2018 at 10:38:04AM +0100, Pierre Moreau wrote:
> On 2018-02-17 13:40, Lukas Wunner wrote:
> > Unbinding nouveau on a dual GPU MacBook Pro oopses because we iterate
> > over the bl_connectors list in nouveau_backlight_exit() but skipped
> > initializing it in nouveau_backlight_init().
> > --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
> > @@ -268,13 +268,13 @@ nouveau_backlight_init(struct drm_device *dev)
> >  	struct nvif_device *device = &drm->client.device;
> >  	struct drm_connector *connector;
> >  
> > +	INIT_LIST_HEAD(&drm->bl_connectors);
> > +
> >  	if (apple_gmux_present()) {
> >  		NV_INFO(drm, "Apple GMUX detected: not registering Nouveau backlight interface\n");
> >  		return 0;
> >  	}
> >  
> > -	INIT_LIST_HEAD(&drm->bl_connectors);
> > -
> 
> We could instead have an early return in the exit function if
> `apple_gmux_present()` or `drm->bl_connectors` is null, but your
> current fix seems better.
> 
> Reviewed-by: Pierre Moreau <pierre.morrow at free.fr>

Hi Ben, just a gentle ping:  I'm not seeing this fix on one of Dave's
branches and neither in your GitHub repo.  I could merge it through
drm-misc-fixes but I'd need an ack from you for that.  Also, please
let me know if you'd prefer the alternative solution Pierre outlined
above.  Thanks!

Lukas