[Intel-gfx] [PATCH] drm/i915: Properly track domain of the fbcon fb

[Chris Wilson]

On Wed, Jun 18, 2014 at 05:57:39PM +0200, Daniel Vetter wrote:
> On Wed, Jun 18, 2014 at 03:57:49PM +0100, Chris Wilson wrote:
> > On Wed, Jun 18, 2014 at 03:05:19PM +0200, Daniel Vetter wrote:
> > > X could end up putting the fbcon fb into other domains, e.g.
> > > for smooth take-overs. Also we want this for accurate frontbuffer
> > > tracking: The set_config is an implicit flush and will re-enable
> > > psr and similar features, so we need to bring the bo back into
> > > the gtt domain.
> > > 
> > > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> > > ---
> > >  drivers/gpu/drm/i915/intel_fbdev.c | 21 ++++++++++++++++++++-
> > >  1 file changed, 20 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> > > index 27975c3e21c5..53c50240d1c2 100644
> > > --- a/drivers/gpu/drm/i915/intel_fbdev.c
> > > +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> > > @@ -43,10 +43,29 @@
> > >  #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) {
> > 
> > Add a comment here saying you are happy with the potential deadlock,
> > double-fault and what not, and I'll accept it with provisons that I'll
> > still worry that this will explode in our faces.
> 
> /*
>  * FIXME: fbdev presumes that all callbacks also work from atomic contexts
>  * and relies on that for emergency oops printing. KMS totally doesn't do
>  * that and the locking here is by far not the only place this goes wrong.
>  * Ignore this for now until we solve this for real.
>  */
> 
> Like this?

That'll do. "Please report all hung systems to <daniel.vetter at ffwll.ch>" would be nice
as well. ;-)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre