drm/nouveau/fb: read TILE_BASE after writing it to avoid a hardware race

Apparently needed for turbocache nv4x chips at least, we'll just do it
everywhere...
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/core/subdev/fb/nv10.c

@@ -54,6 +54,7 @@ nv10_fb_tile_prog(struct nouveau_fb *pfb, int i, struct nouveau_fb_tile *tile)
 	nv_wr32(pfb, 0x100244 + (i * 0x10), tile->limit);
 	nv_wr32(pfb, 0x100248 + (i * 0x10), tile->pitch);
 	nv_wr32(pfb, 0x100240 + (i * 0x10), tile->addr);
+	nv_rd32(pfb, 0x100240 + (i * 0x10));
 }
 
 static int

drivers/gpu/drm/nouveau/core/subdev/fb/nv20.c

@@ -83,6 +83,7 @@ nv20_fb_tile_prog(struct nouveau_fb *pfb, int i, struct nouveau_fb_tile *tile)
 	nv_wr32(pfb, 0x100244 + (i * 0x10), tile->limit);
 	nv_wr32(pfb, 0x100248 + (i * 0x10), tile->pitch);
 	nv_wr32(pfb, 0x100240 + (i * 0x10), tile->addr);
+	nv_rd32(pfb, 0x100240 + (i * 0x10));
 	nv_wr32(pfb, 0x100300 + (i * 0x04), tile->zcomp);
 }
 

drivers/gpu/drm/nouveau/core/subdev/fb/nv41.c

@@ -36,6 +36,7 @@ nv41_fb_tile_prog(struct nouveau_fb *pfb, int i, struct nouveau_fb_tile *tile)
 	nv_wr32(pfb, 0x100604 + (i * 0x10), tile->limit);
 	nv_wr32(pfb, 0x100608 + (i * 0x10), tile->pitch);
 	nv_wr32(pfb, 0x100600 + (i * 0x10), tile->addr);
+	nv_rd32(pfb, 0x100600 + (i * 0x10));
 	nv_wr32(pfb, 0x100700 + (i * 0x04), tile->zcomp);
 }
 

drivers/gpu/drm/nouveau/core/subdev/fb/nv44.c

@@ -46,6 +46,7 @@ nv44_fb_tile_prog(struct nouveau_fb *pfb, int i, struct nouveau_fb_tile *tile)
 	nv_wr32(pfb, 0x100604 + (i * 0x10), tile->limit);
 	nv_wr32(pfb, 0x100608 + (i * 0x10), tile->pitch);
 	nv_wr32(pfb, 0x100600 + (i * 0x10), tile->addr);
+	nv_rd32(pfb, 0x100600 + (i * 0x10));
 }
 
 int