[PATCH 4/6] modesetting: reverse prime support

[Dave Airlie]

>> +
>> +        screenpix = screen->GetScreenPixmap(screen);
>> +        screen->width = screenpix->drawable.width = total_width;
>> +        screen->height = screenpix->drawable.height = max_height;
>
> Directly setting the width/height of a pixmap?  That seems suspicious to
> me.  Usually you're using ModifyPixmapHeader(), since you need to change
> other things (like the pointer/stride) at the same time.  Is there an
> explanation for this being safe?

I just pre-existing precedent for this

xf86RandR12.c:xf86RandR12ScreenSetSize

after it calls the driver resize hook does
   pScrnPix = (*pScreen->GetScreenPixmap) (pScreen);
    pScreen->width = pScrnPix->drawable.width = width;
    pScreen->height = pScrnPix->drawable.height = height;

and since I'm doing pretty much the same thing resizing the screen,
I used the code from there.

Dave.