drm/nouveau/dp: fix support for dpms

SOR_PWR has no effect to power-off DP links, unlike other SOR protocols.

Instead, on the source side, we cut power to the lanes after having put
the sink into D3.  Link training takes care of everything required to
bring it back again.

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

1 files changed, 37 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 7535a87..7dac5e2 100644
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -76,7 +76,8 @@ find_encoder(struct drm_connector *connector, int type)
 			continue;
 		nv_encoder = nouveau_encoder(obj_to_encoder(obj));
 
-		if (type == DCB_OUTPUT_ANY || nv_encoder->dcb->type == type)
+		if (type == DCB_OUTPUT_ANY ||
+		    (nv_encoder->dcb && nv_encoder->dcb->type == type))
 			return nv_encoder;
 	}
 
@@ -915,6 +916,40 @@ nouveau_connector_funcs_lvds = {
 };
 
 static void
+nouveau_connector_dp_dpms(struct drm_connector *connector, int mode)
+{
+	struct nouveau_encoder *nv_encoder = NULL;
+
+	if (connector->encoder)
+		nv_encoder = nouveau_encoder(connector->encoder);
+	if (nv_encoder && nv_encoder->dcb &&
+	    nv_encoder->dcb->type == DCB_OUTPUT_DP) {
+		if (mode == DRM_MODE_DPMS_ON) {
+			u8 data = DP_SET_POWER_D0;
+			nv_wraux(nv_encoder->i2c, DP_SET_POWER, &data, 1);
+			usleep_range(1000, 2000);
+		} else {
+			u8 data = DP_SET_POWER_D3;
+			nv_wraux(nv_encoder->i2c, DP_SET_POWER, &data, 1);
+		}
+	}
+
+	drm_helper_connector_dpms(connector, mode);
+}
+
+static const struct drm_connector_funcs
+nouveau_connector_funcs_dp = {
+	.dpms = nouveau_connector_dp_dpms,
+	.save = NULL,
+	.restore = NULL,
+	.detect = nouveau_connector_detect,
+	.destroy = nouveau_connector_destroy,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.set_property = nouveau_connector_set_property,
+	.force = nouveau_connector_force
+};
+
+static void
 nouveau_connector_hotplug_work(struct work_struct *work)
 {
 	struct nouveau_connector *nv_connector =
@@ -1122,7 +1157,7 @@ nouveau_connector_create(struct drm_device *dev, int index)
 			return ERR_PTR(ret);
 		}
 
-		funcs = &nouveau_connector_funcs;
+		funcs = &nouveau_connector_funcs_dp;
 		break;
 	default:
 		funcs = &nouveau_connector_funcs;