drm/nv50: preserve an unknown SOR_MODECTRL value for DP encoders
This value interacts with some registers we don't currently know how to
program properly ourselves. The default of 5 that we were using matches
what the VBIOS on early DP cards do, but later ones use 6, which would
cause nouveau to program an incorrect mode on these chips.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_encoder.h b/drivers/gpu/drm/nouveau/nouveau_encoder.h
index bc4a240..9f28b94 100644
--- a/drivers/gpu/drm/nouveau/nouveau_encoder.h
+++ b/drivers/gpu/drm/nouveau/nouveau_encoder.h
@@ -47,6 +47,7 @@
union {
struct {
+ int mc_unknown;
int dpcd_version;
int link_nr;
int link_bw;
diff --git a/drivers/gpu/drm/nouveau/nv50_sor.c b/drivers/gpu/drm/nouveau/nv50_sor.c
index c2fff54..e31ba31 100644
--- a/drivers/gpu/drm/nouveau/nv50_sor.c
+++ b/drivers/gpu/drm/nouveau/nv50_sor.c
@@ -211,7 +211,7 @@
mode_ctl = 0x0200;
break;
case OUTPUT_DP:
- mode_ctl |= 0x00050000;
+ mode_ctl |= (nv_encoder->dp.mc_unknown << 16);
if (nv_encoder->dcb->sorconf.link & 1)
mode_ctl |= 0x00000800;
else
@@ -274,6 +274,7 @@
int
nv50_sor_create(struct drm_device *dev, struct dcb_entry *entry)
{
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
struct nouveau_encoder *nv_encoder = NULL;
struct drm_encoder *encoder;
bool dum;
@@ -319,5 +320,24 @@
encoder->possible_crtcs = entry->heads;
encoder->possible_clones = 0;
+ if (nv_encoder->dcb->type == OUTPUT_DP) {
+ uint32_t mc, or = nv_encoder->or;
+
+ if (dev_priv->chipset < 0x90 ||
+ dev_priv->chipset == 0x92 || dev_priv->chipset == 0xa0)
+ mc = nv_rd32(dev, NV50_PDISPLAY_SOR_MODE_CTRL_C(or));
+ else
+ mc = nv_rd32(dev, NV90_PDISPLAY_SOR_MODE_CTRL_C(or));
+
+ switch ((mc & 0x00000f00) >> 8) {
+ case 8:
+ case 9:
+ nv_encoder->dp.mc_unknown = (mc & 0x000f0000) >> 16;
+ break;
+ default:
+ break;
+ }
+ }
+
return 0;
}