drm/nv20-nv40: add memory type detection

NV20/NV30 is partially educated guesswork at this point, based on any
information around about available memory types and a horribly unspeakable
amount of vbios image scouring.  I'm not entirely certain the GDDR3 define
is correct, I have not spotted a single vbios with that value yet (though
it is mentioned in some 1218-using nv4x vbios), but there are reports that
some nv3x did use it..

NV40(100914) confirmed by switching an NV49 to DDR1/DDR2 values and making
sure that the binary driver behaviour showed it had detected DDR1/DDR2
instead of GDDR3 before dying horribly.

NV40(100474) confirmed by doing much the same task as above on an NV44,
except this was *much* easier as changing the values didn't seem to have
any noticable effect on the memory controller aside from changing the
binary driver's behaviour.

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

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nv20_fb.c b/drivers/gpu/drm/nouveau/nv20_fb.c
index 6585c27186d..19bd64059a6 100644
--- a/drivers/gpu/drm/nouveau/nv20_fb.c
+++ b/drivers/gpu/drm/nouveau/nv20_fb.c
@@ -100,8 +100,17 @@ int
 nv20_fb_vram_init(struct drm_device *dev)
 {
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	u32 mem_size = nv_rd32(dev, 0x10020c);
+	u32 pbus1218 = nv_rd32(dev, 0x001218);
+
+	dev_priv->vram_size = mem_size & 0xff000000;
+	switch (pbus1218 & 0x00000300) {
+	case 0x00000000: dev_priv->vram_type = NV_MEM_TYPE_SDRAM; break;
+	case 0x00000100: dev_priv->vram_type = NV_MEM_TYPE_DDR1; break;
+	case 0x00000200: dev_priv->vram_type = NV_MEM_TYPE_GDDR3; break;
+	case 0x00000300: dev_priv->vram_type = NV_MEM_TYPE_GDDR2; break;
+	}
 
-	dev_priv->vram_size = nv_rd32(dev, 0x10020c) & 0xff000000;
 	return 0;
 }