[Intel-gfx] [PATCH 14/15] drm/i915: Track frontbuffer invalidation/flushing

[Chris Wilson]

On Tue, Jun 17, 2014 at 09:32:47AM +0200, Daniel Vetter wrote:
> On Tue, Jun 17, 2014 at 07:41:48AM +0100, Chris Wilson wrote:
> > On Mon, Jun 16, 2014 at 07:51:34PM +0200, Daniel Vetter wrote:
> > > diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> > > index 27975c3e21c5..12276c39d14d 100644
> > > --- a/drivers/gpu/drm/i915/intel_fbdev.c
> > > +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> > > @@ -43,10 +43,26 @@
> > >  #include <drm/i915_drm.h>
> > >  #include "i915_drv.h"
> > >  
> > > +static int intel_fbdev_set_par(struct fb_info *info)
> > > +{
> > > +	struct drm_fb_helper *fb_helper = info->par;
> > > +	struct intel_fbdev *ifbdev =
> > > +		container_of(fb_helper, struct intel_fbdev, helper);
> > > +	int ret;
> > > +
> > > +	ret = drm_fb_helper_set_par(info);
> > > +
> > > +	if (ret == 0)
> > > +		ret = i915_gem_object_set_to_gtt_domain(ifbdev->fb->obj,
> > > +							true);
> > > +
> > > +	return ret;
> > > +}
> > 
> > Ah, I had missed you added this. Yes, this is what I had in mind for
> > fixing fbcon. However, this is worth splitting out into a separate path
> > as this is about to get hairy!
> > 
> > ret = drm_fb_helper_set_par(info)
> > if (ret) return ret;
> > 
> >  /* Invalidate the fb for all further writes whilst on the console */
> >  if (!in_atomic() && mutex_trylock(&dev->struct_mutex)) {
> >    ret = i915_gem_object_set_tp_gtt_domain(obj, true);
> >    mutex_unlock(&dev->srtuct_mutex);
> >   }
> >  return ret;
> 
> We already have ridiculous amounts of not trylocked state in set_par, so
> doing this won't help really. And fixing up the emergency console logic is
> imo out of scope for this ;-)

But at least separate the dubious from the rest of the patch. :)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre