drm/radeon: fix problem with changing active VRAM size. (v2)

So we used to use lpfn directly to restrict VRAM when we couldn't
access the unmappable area, however this was removed in
93225b0d7bc030f4a93165347a65893685822d70 as it also restricted
the gtt placements. However it was only later noticed that this
broke on some hw.

This removes the active_vram_size, and just explicitly sets it
when it changes, TTM/drm_mm will always use the real_vram_size,
and the active vram size will change the TTM size used for lpfn
setting.

We should re-work the fpfn/lpfn to per-placement at some point
I suspect, but that is too late for this kernel.

Hopefully this addresses:
https://bugs.freedesktop.org/show_bug.cgi?id=35254

v2: fix reported useful VRAM size to userspace to be correct.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index de88624d5f87..9b3fad23b76c 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1255,7 +1255,6 @@ int r600_mc_init(struct radeon_device *rdev)
         rdev->mc.mc_vram_size = RREG32(CONFIG_MEMSIZE);
         rdev->mc.real_vram_size = RREG32(CONFIG_MEMSIZE);
         rdev->mc.visible_vram_size = rdev->mc.aper_size;
-        rdev->mc.active_vram_size = rdev->mc.visible_vram_size;
         r600_vram_gtt_location(rdev, &rdev->mc);
 
         if (rdev->flags & RADEON_IS_IGP) {
@@ -1937,7 +1936,7 @@ void r600_pciep_wreg(struct radeon_device *rdev, u32 reg, u32 v)
  */
 void r600_cp_stop(struct radeon_device *rdev)
 {
-        rdev->mc.active_vram_size = rdev->mc.visible_vram_size;
+        radeon_ttm_set_active_vram_size(rdev, rdev->mc.visible_vram_size);
         WREG32(R_0086D8_CP_ME_CNTL, S_0086D8_CP_ME_HALT(1));
         WREG32(SCRATCH_UMSK, 0);
 }