drm/nv40: fall back to paged dma object for the moment

PCI(E)GART isn't quite stable it seems, fall back to old method until I get
the time to sort it out properly.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_mem.c

@@ -397,7 +397,7 @@ nouveau_mem_vram_init(struct drm_device *dev)
 		if (pci_dma_supported(dev->pdev, DMA_BIT_MASK(40)))
 			dma_bits = 40;
 	} else
-	if (drm_pci_device_is_pcie(dev) &&
+	if (0 && drm_pci_device_is_pcie(dev) &&
 	    dev_priv->chipset  > 0x40 &&
 	    dev_priv->chipset != 0x45) {
 		if (pci_dma_supported(dev->pdev, DMA_BIT_MASK(39)))

drivers/gpu/drm/nouveau/nouveau_sgdma.c

@@ -458,7 +458,7 @@ nouveau_sgdma_init(struct drm_device *dev)
 		dev_priv->gart_info.type = NOUVEAU_GART_HW;
 		dev_priv->gart_info.func = &nv50_sgdma_backend;
 	} else
-	if (drm_pci_device_is_pcie(dev) &&
+	if (0 && drm_pci_device_is_pcie(dev) &&
 	    dev_priv->chipset > 0x40 && dev_priv->chipset != 0x45) {
 		if (nv44_graph_class(dev)) {
 			dev_priv->gart_info.func = &nv44_sgdma_backend;