drm/nvd0-/disp: handle case where display engine is missing/disabled

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

drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c

@@ -958,6 +958,9 @@ nvd0_disp_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 	int heads = nv_rd32(parent, 0x022448);
 	int ret;
 
+	if (nv_rd32(parent, 0x022500) & 0x00000001)
+		return -ENODEV;
+
 	ret = nouveau_disp_create(parent, engine, oclass, heads,
 				  "PDISP", "display", &priv);
 	*pobject = nv_object(priv);

drivers/gpu/drm/nouveau/core/engine/disp/nve0.c

@@ -54,6 +54,9 @@ nve0_disp_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 	int heads = nv_rd32(parent, 0x022448);
 	int ret;
 
+	if (nv_rd32(parent, 0x022500) & 0x00000001)
+		return -ENODEV;
+
 	ret = nouveau_disp_create(parent, engine, oclass, heads,
 				  "PDISP", "display", &priv);
 	*pobject = nv_object(priv);

drivers/gpu/drm/nouveau/core/engine/disp/nvf0.c

@@ -54,6 +54,9 @@ nvf0_disp_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 	int heads = nv_rd32(parent, 0x022448);
 	int ret;
 
+	if (nv_rd32(parent, 0x022500) & 0x00000001)
+		return -ENODEV;
+
 	ret = nouveau_disp_create(parent, engine, oclass, heads,
 				  "PDISP", "display", &priv);
 	*pobject = nv_object(priv);

drivers/gpu/drm/nouveau/core/subdev/bios/base.c

@@ -85,11 +85,15 @@ static void
 nouveau_bios_shadow_pramin(struct nouveau_bios *bios)
 {
 	struct nouveau_device *device = nv_device(bios);
+	u64 addr = 0;
 	u32 bar0 = 0;
 	int i;
 
 	if (device->card_type >= NV_50) {
-		u64 addr = (u64)(nv_rd32(bios, 0x619f04) & 0xffffff00) << 8;
+		if (  device->card_type < NV_C0 ||
+		    !(nv_rd32(bios, 0x022500) & 0x00000001))
+			addr = (u64)(nv_rd32(bios, 0x619f04) & 0xffffff00) << 8;
+
 		if (!addr) {
 			addr  = (u64)nv_rd32(bios, 0x001700) << 16;
 			addr += 0xf0000;

drivers/gpu/drm/nouveau/core/subdev/devinit/nvc0.c

@@ -73,6 +73,8 @@ nvc0_devinit_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 		return ret;
 
 	priv->base.pll_set = nvc0_devinit_pll_set;
+	if (nv_rd32(priv, 0x022500) & 0x00000001)
+		priv->base.post = true;
 	return 0;
 }
 

drivers/gpu/drm/nouveau/nouveau_bios.c

@@ -2051,19 +2051,14 @@ nouveau_bios_posted(struct drm_device *dev)
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	unsigned htotal;
 
-	if (nv_device(drm->device)->card_type >= NV_50) {
-		if (NVReadVgaCrtc(dev, 0, 0x00) == 0 &&
-		    NVReadVgaCrtc(dev, 0, 0x1a) == 0)
-			return false;
+	if (nv_device(drm->device)->card_type >= NV_50)
 		return true;
-	}
 
 	htotal  = NVReadVgaCrtc(dev, 0, 0x06);
 	htotal |= (NVReadVgaCrtc(dev, 0, 0x07) & 0x01) << 8;
 	htotal |= (NVReadVgaCrtc(dev, 0, 0x07) & 0x20) << 4;
 	htotal |= (NVReadVgaCrtc(dev, 0, 0x25) & 0x01) << 10;
 	htotal |= (NVReadVgaCrtc(dev, 0, 0x41) & 0x01) << 11;
-
 	return (htotal != 0);
 }