[PATCH 1/2] drm: Add drm_gem_vram_{pin/unpin}_reserved() and convert mgag200

[Gerd Hoffmann]

  Hi,

> I think would be good to have a lockdep_assert_held here for the ww_mutex.
> 
> Also general thing: _reserved is kinda ttm lingo, for dma-buf reservations
> we call the structure tracking the fences+lock the "reservation", but the
> naming scheme used is _lock/_unlock.
> 
> I think would be good to be consistent with that, and use _locked here.
> Especially for a very simplified vram helper like this one I expect that's
> going to lead to less wtf moments by driver writers :-)
> 
> Maybe we should also do a large-scale s/reserve/lock/ within ttm, to align
> more with what we now have in dma-buf.

Given that mgag200 is the only user I think the best way forward is to
improve the mgag200 cursor handling so we can just drop the _reserved
variants ...

When looking at mga_crtc_cursor_set() I suspect the easierst way to do
that would be to simply pin the cursor bo's at driver_load time, then we
don't have to bother with pinning in mga_crtc_cursor_set() at all.

Thomas, as you have test hardware, can you look into this?

thanks,
  Gerd