[PATCH xf86-video-ati 1/2] dri2: Update front buffer pixmap and name before exchanging buffers

[Ville Syrjälä]

On Thu, May 05, 2011 at 12:28:20PM +0200, Michel Dänzer wrote:
> On Mit, 2011-05-04 at 23:51 +0300, Ville Syrjala wrote: 
> > Buffer exchange assumes that the front buffer pixmap and name
> > information is accurate. That may not be the case eg. if the window
> > has been (un)redirected since the buffer was created.
> > 
> > Signed-off-by: Ville Syrjala <syrjala at sci.fi>
> > ---
> >  src/radeon_dri2.c |   45 ++++++++++++++++++++++++++++++++++++++++-----
> >  1 files changed, 40 insertions(+), 5 deletions(-)
> > 
> > diff --git a/src/radeon_dri2.c b/src/radeon_dri2.c
> > index e618cc5..5d1a382 100644
> > --- a/src/radeon_dri2.c
> > +++ b/src/radeon_dri2.c
> > @@ -626,12 +626,42 @@ radeon_dri2_schedule_flip(ScrnInfoPtr scrn, ClientPtr client,
> >  }
> >  
> >  static Bool
> > -can_exchange(ScrnInfoPtr pScrn,
> > +update_front(DrawablePtr draw, DRI2BufferPtr front)
> > +{
> > +    int r;
> > +    PixmapPtr pixmap;
> > +    struct dri2_buffer_priv *priv = front->driverPrivate;
> > +    struct radeon_exa_pixmap_priv *driver_priv;
> > +
> > +    if (draw->type == DRAWABLE_PIXMAP)
> > +	pixmap = (PixmapPtr)draw;
> > +    else
> > +	pixmap = (*draw->pScreen->GetWindowPixmap)((WindowPtr)draw);
> > +
> > +    pixmap->refcnt++;
> > +
> > +    exaMoveInPixmap(pixmap);
> > +    driver_priv = exaGetPixmapDriverPrivate(pixmap);
> > +    r = radeon_gem_get_kernel_name(driver_priv->bo, &front->name);
> > +    if (r) {
> > +	(*draw->pScreen->DestroyPixmap)(pixmap);
> > +	return FALSE;
> > +    }
> > +    (*draw->pScreen->DestroyPixmap)(priv->pixmap);
> > +    front->pitch = pixmap->devKind;
> > +    front->cpp = pixmap->drawable.bitsPerPixel / 8;
> > +    priv->pixmap = pixmap;
> > +
> > +    return TRUE;
> > +}
> 
> Maybe at least some of this could be short-circuited if it's still the
> same pixmap.

Yeah, I had the same thought. There's one catch though; Even if it's the
same pixmap, the bo may have been exchanged, and so the buffer name may
need to be updated anyway.

-- 
Ville Syrjälä
syrjala at sci.fi
http://www.sci.fi/~syrjala/