diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index 1f472ff..30e4593 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -4883,10 +4883,15 @@ static int parse_bmp_structure(struct drm_device *dev, struct nvbios *bios, unsi
 	bios->legacy.i2c_indices.crt = bios->data[legacy_i2c_offset];
 	bios->legacy.i2c_indices.tv = bios->data[legacy_i2c_offset + 1];
 	bios->legacy.i2c_indices.panel = bios->data[legacy_i2c_offset + 2];
-	bios->bdcb.dcb.i2c[0].write = bios->data[legacy_i2c_offset + 4];
-	bios->bdcb.dcb.i2c[0].read = bios->data[legacy_i2c_offset + 5];
-	bios->bdcb.dcb.i2c[1].write = bios->data[legacy_i2c_offset + 6];
-	bios->bdcb.dcb.i2c[1].read = bios->data[legacy_i2c_offset + 7];
+	/* don't overwrite defaults with zero (mac braindamage) */
+	if (bios->data[legacy_i2c_offset + 4])
+		bios->bdcb.dcb.i2c[0].write = bios->data[legacy_i2c_offset + 4];
+	if (bios->data[legacy_i2c_offset + 5])
+		bios->bdcb.dcb.i2c[0].read = bios->data[legacy_i2c_offset + 5];
+	if (bios->data[legacy_i2c_offset + 6])
+		bios->bdcb.dcb.i2c[1].write = bios->data[legacy_i2c_offset + 6];
+	if (bios->data[legacy_i2c_offset + 7])
+		bios->bdcb.dcb.i2c[1].read = bios->data[legacy_i2c_offset + 7];
 
 	if (bmplength > 74) {
 		bios->fmaxvco = ROM32(bmp[67]);
@@ -5130,6 +5135,7 @@ static void fabricate_vga_output(struct parsed_dcb *dcb, int i2c, int heads)
 	entry->heads = heads;
 	entry->location = DCB_LOC_ON_CHIP;
 	/* "or" mostly unused in early gen crt modesetting, 0 is fine */
+	entry->or = 1;
 }
 
 static void fabricate_dvi_i_output(struct parsed_dcb *dcb, bool twoHeads)