[PATCH] dri2: Don't page flip when the window size doesn't match the pixmap size

[Ville Syrjälä]

On Fri, Dec 03, 2010 at 08:23:16PM +0200, ville.syrjala at nokia.com wrote:
> From: Ville Syrjälä <ville.syrjala at nokia.com>
> 
> If the drawable size doesn't match the pixmap size page flipping should
> not be allowed.
> 
> If the window is larger than the pixmap, page flipping might need to
> reposition the CRTC somewhere in the middle of the pixmap. I didn't
> spot any code that would handle that at least in the intel driver.
> 
> Also the root pixmap could then move to some negative screen
> coordinates. Not sure if all bits of code could handle that. Perhaps
> when composite is enabled screen_x/y would make it work, but without
> composite there's no way that it would work AFAICS.

Ping. Any comments on this?

> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at nokia.com>
> ---
>  hw/xfree86/dri2/dri2.c |   11 +++++++++++
>  1 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
> index 7bcd788..1622f69 100644
> --- a/hw/xfree86/dri2/dri2.c
> +++ b/hw/xfree86/dri2/dri2.c
> @@ -699,6 +699,17 @@ DRI2CanFlip(DrawablePtr pDraw)
>      if (!RegionEqual(&pWin->clipList, &pRoot->winSize))
>  	return FALSE;
>  
> +    /* Does the window match the pixmap exactly? */
> +    if (pDraw->x != 0 ||
> +	pDraw->y != 0 ||
> +#ifdef COMPOSITE
> +	pDraw->x != pWinPixmap->screen_x ||
> +	pDraw->y != pWinPixmap->screen_y ||
> +#endif
> +	pDraw->width != pWinPixmap->drawable.width ||
> +	pDraw->height != pWinPixmap->drawable.height)
> +	return FALSE;
> +
>      return TRUE;
>  }
>  
> -- 
> 1.7.2.2
> 

-- 
Ville Syrjälä