{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
+ repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
struct drm_dp_mst_port *port)
{
mutex_lock(&mgr->lock);
+ port->parent->num_ports--;
list_del(&port->next);
mutex_unlock(&mgr->lock);
drm_dp_mst_topology_put_port(port);
mutex_lock(&mgr->lock);
drm_dp_mst_topology_get_port(port);
list_add(&port->next, &mstb->ports);
+ mstb->num_ports++;
mutex_unlock(&mgr->lock);
}
path_res->avail_payload_bw_number);
port->available_pbn =
path_res->avail_payload_bw_number;
+ port->fec_capable = path_res->fec_capable;
}
}
{
i2c_del_adapter(&aux->ddc);
}
+
+/**
+ * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
+ * @port: The port to check
+ *
+ * A single physical MST hub object can be represented in the topology
+ * by multiple branches, with virtual ports between those branches.
+ *
+ * As of DP1.4, An MST hub with internal (virtual) ports must expose
+ * certain DPCD registers over those ports. See sections 2.6.1.1.1
+ * and 2.6.1.1.2 of Display Port specification v1.4 for details.
+ *
+ * May acquire mgr->lock
+ *
+ * Returns:
+ * true if the port is a virtual DP peer device, false otherwise
+ */
+static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
+{
+ struct drm_dp_mst_port *downstream_port;
+
+ if (!port || port->dpcd_rev < DP_DPCD_REV_14)
+ return false;
+
+ /* Virtual DP Sink (Internal Display Panel) */
+ if (port->port_num >= 8)
+ return true;
+
+ /* DP-to-HDMI Protocol Converter */
+ if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
+ !port->mcs &&
+ port->ldps)
+ return true;
+
+ /* DP-to-DP */
+ mutex_lock(&port->mgr->lock);
+ if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+ port->mstb &&
+ port->mstb->num_ports == 2) {
+ list_for_each_entry(downstream_port, &port->mstb->ports, next) {
+ if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
+ !downstream_port->input) {
+ mutex_unlock(&port->mgr->lock);
+ return true;
+ }
+ }
+ }
+ mutex_unlock(&port->mgr->lock);
+
+ return false;
+}
+
+/**
+ * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
+ * @port: The port to check. A leaf of the MST tree with an attached display.
+ *
+ * Depending on the situation, DSC may be enabled via the endpoint aux,
+ * the immediately upstream aux, or the connector's physical aux.
+ *
+ * This is both the correct aux to read DSC_CAPABILITY and the
+ * correct aux to write DSC_ENABLED.
+ *
+ * This operation can be expensive (up to four aux reads), so
+ * the caller should cache the return.
+ *
+ * Returns:
+ * NULL if DSC cannot be enabled on this port, otherwise the aux device
+ */
+struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
+{
+ struct drm_dp_mst_port *immediate_upstream_port;
+ struct drm_dp_mst_port *fec_port;
+ struct drm_dp_desc desc = { 0 };
+ u8 endpoint_fec;
+ u8 endpoint_dsc;
+
+ if (!port)
+ return NULL;
+
+ if (port->parent->port_parent)
+ immediate_upstream_port = port->parent->port_parent;
+ else
+ immediate_upstream_port = NULL;
+
+ fec_port = immediate_upstream_port;
+ while (fec_port) {
+ /*
+ * Each physical link (i.e. not a virtual port) between the
+ * output and the primary device must support FEC
+ */
+ if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
+ !fec_port->fec_capable)
+ return NULL;
+
+ fec_port = fec_port->parent->port_parent;
+ }
+
+ /* DP-to-DP peer device */
+ if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
+ u8 upstream_dsc;
+
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
+ DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
+ return NULL;
+
+ /* Enpoint decompression with DP-to-DP peer device */
+ if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
+ (endpoint_fec & DP_FEC_CAPABLE) &&
+ (upstream_dsc & 0x2) /* DSC passthrough */)
+ return &port->aux;
+
+ /* Virtual DPCD decompression with DP-to-DP peer device */
+ return &immediate_upstream_port->aux;
+ }
+
+ /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
+ if (drm_dp_mst_is_virtual_dpcd(port))
+ return &port->aux;
+
+ /*
+ * Synaptics quirk
+ * Applies to ports for which:
+ * - Physical aux has Synaptics OUI
+ * - DPv1.4 or higher
+ * - Port is on primary branch device
+ * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
+ */
+ if (drm_dp_read_desc(port->mgr->aux, &desc, true))
+ return NULL;
+
+ if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
+ port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
+ port->parent == port->mgr->mst_primary) {
+ u8 downstreamport;
+
+ if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
+ &downstreamport, 1) < 0)
+ return NULL;
+
+ if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
+ ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
+ != DP_DWN_STRM_PORT_TYPE_ANALOG))
+ return port->mgr->aux;
+ }
+
+ /*
+ * The check below verifies if the MST sink
+ * connected to the GPU is capable of DSC -
+ * therefore the endpoint needs to be
+ * both DSC and FEC capable.
+ */
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+ return NULL;
+ if (drm_dp_dpcd_read(&port->aux,
+ DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+ return NULL;
+ if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
+ (endpoint_fec & DP_FEC_CAPABLE))
+ return &port->aux;
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
projects / linux.git / blobdiff