Re: [PATCH 14/15] drm/i915: Track frontbuffer invalidation/flushing

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Jun 17, 2014 at 08:36:48AM +0100, Chris Wilson wrote:
> 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. :)

Yeah, split out now.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch