drm/nv50: fix DP->DVI if output has been programmed for native DP previously
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index e031904..0c76204 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -821,6 +821,36 @@
}
}
+/* If programming a TMDS output on a SOR that can also be configured for
+ * DisplayPort, make sure NV50_SOR_DP_CTRL_ENABLE is forced off.
+ *
+ * It looks like the VBIOS TMDS scripts make an attempt at this, however,
+ * the VBIOS scripts on at least one board I have only switch it off on
+ * link 0, causing a blank display if the output has previously been
+ * programmed for DisplayPort.
+ */
+static void
+nv50_display_unk20_dp_set_tmds(struct drm_device *dev, struct dcb_entry *dcb)
+{
+ int or = ffs(dcb->or) - 1, link = !(dcb->dpconf.sor.link & 1);
+ struct drm_encoder *encoder;
+ u32 tmp;
+
+ if (dcb->type != OUTPUT_TMDS)
+ return;
+
+ list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+ struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
+
+ if (nv_encoder->dcb->type == OUTPUT_DP) {
+ tmp = nv_rd32(dev, NV50_SOR_DP_CTRL(or, link));
+ tmp &= ~NV50_SOR_DP_CTRL_ENABLED;
+ nv_wr32(dev, NV50_SOR_DP_CTRL(or, link), tmp);
+ break;
+ }
+ }
+}
+
static void
nv50_display_unk20_handler(struct drm_device *dev)
{
@@ -845,6 +875,7 @@
nouveau_bios_run_display_table(dev, dcbent, script, pclk);
nv50_display_unk20_dp_hack(dev, dcbent);
+ nv50_display_unk20_dp_set_tmds(dev, dcbent);
tmp = nv_rd32(dev, NV50_PDISPLAY_CRTC_CLK_CTRL2(head));
tmp &= ~0x000000f;