diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 468 |
1 files changed, 459 insertions, 9 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index e6afe4faeca6..20cdaf3146b8 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -76,6 +76,11 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb); + +static void +drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_branch *mstb); + static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *port); @@ -517,8 +522,10 @@ drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, } if (failed) { - for (i = 0; i < r->num_transactions; i++) + for (i = 0; i < r->num_transactions; i++) { + tx = &r->transactions[i]; kfree(tx->bytes); + } return -ENOMEM; } @@ -846,6 +853,7 @@ static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband { 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; @@ -950,6 +958,8 @@ static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, case DP_POWER_DOWN_PHY: case DP_POWER_UP_PHY: return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); + case DP_CLEAR_PAYLOAD_ID_TABLE: + return true; /* since there's nothing to parse */ default: DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); @@ -1048,6 +1058,15 @@ static int build_link_address(struct drm_dp_sideband_msg_tx *msg) return 0; } +static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) +{ + struct drm_dp_sideband_msg_req_body req; + + req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; + drm_dp_encode_sideband_req(&req, msg); + return 0; +} + static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num) { struct drm_dp_sideband_msg_req_body req; @@ -2175,6 +2194,7 @@ drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 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); @@ -2199,6 +2219,9 @@ drm_dp_mst_add_port(struct drm_device *dev, port->aux.dev = dev->dev; port->aux.is_remote = true; + /* initialize the MST downstream port's AUX crc work queue */ + drm_dp_remote_aux_init(&port->aux); + /* * Make sure the memory allocation for our parent branch stays * around until our own memory allocation is released @@ -2275,6 +2298,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, mutex_lock(&mgr->lock); drm_dp_mst_topology_get_port(port); list_add(&port->next, &mstb->ports); + mstb->num_ports++; mutex_unlock(&mgr->lock); } @@ -2564,10 +2588,14 @@ static void drm_dp_mst_link_probe_work(struct work_struct *work) struct drm_device *dev = mgr->dev; struct drm_dp_mst_branch *mstb; int ret; + bool clear_payload_id_table; mutex_lock(&mgr->probe_lock); mutex_lock(&mgr->lock); + clear_payload_id_table = !mgr->payload_id_table_cleared; + mgr->payload_id_table_cleared = true; + mstb = mgr->mst_primary; if (mstb) { ret = drm_dp_mst_topology_try_get_mstb(mstb); @@ -2580,6 +2608,19 @@ static void drm_dp_mst_link_probe_work(struct work_struct *work) return; } + /* + * Certain branch devices seem to incorrectly report an available_pbn + * of 0 on downstream sinks, even after clearing the + * DP_PAYLOAD_ALLOCATE_* registers in + * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C + * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make + * things work again. + */ + if (clear_payload_id_table) { + DRM_DEBUG_KMS("Clearing payload ID table\n"); + drm_dp_send_clear_payload_id_table(mgr, mstb); + } + ret = drm_dp_check_and_send_link_address(mgr, mstb); drm_dp_mst_topology_put_mstb(mstb); @@ -2906,6 +2947,28 @@ out: return ret < 0 ? ret : changed; } +void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_branch *mstb) +{ + struct drm_dp_sideband_msg_tx *txmsg; + int len, ret; + + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); + if (!txmsg) + return; + + txmsg->dst = mstb; + len = build_clear_payload_id_table(txmsg); + + drm_dp_queue_down_tx(mgr, txmsg); + + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); + if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) + DRM_DEBUG_KMS("clear payload table id nak received\n"); + + kfree(txmsg); +} + static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb, @@ -2941,6 +3004,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, path_res->avail_payload_bw_number); port->available_pbn = path_res->avail_payload_bw_number; + port->fec_capable = path_res->fec_capable; } } @@ -3435,6 +3499,7 @@ static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) { int ret = 0; + int i = 0; struct drm_dp_mst_branch *mstb = NULL; mutex_lock(&mgr->lock); @@ -3495,10 +3560,23 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms /* this can fail if the device is gone */ drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); ret = 0; + mutex_lock(&mgr->payload_lock); memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload)); mgr->payload_mask = 0; set_bit(0, &mgr->payload_mask); + for (i = 0; i < mgr->max_payloads; i++) { + struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; + + if (vcpi) { + vcpi->vcpi = 0; + vcpi->num_slots = 0; + } + mgr->proposed_vcpis[i] = NULL; + } mgr->vcpi_mask = 0; + mutex_unlock(&mgr->payload_lock); + + mgr->payload_id_table_cleared = false; } out_unlock: @@ -4071,6 +4149,7 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, * @mgr: MST topology manager for the port * @port: port to find vcpi slots for * @pbn: bandwidth required for the mode in PBN + * @pbn_div: divider for DSC mode that takes FEC into account * * Allocates VCPI slots to @port, replacing any previous VCPI allocations it * may have had. Any atomic drivers which support MST must call this function @@ -4097,11 +4176,12 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, */ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, - struct drm_dp_mst_port *port, int pbn) + struct drm_dp_mst_port *port, int pbn, + int pbn_div) { struct drm_dp_mst_topology_state *topology_state; struct drm_dp_vcpi_allocation *pos, *vcpi = NULL; - int prev_slots, req_slots; + int prev_slots, prev_bw, req_slots; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) @@ -4112,6 +4192,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, if (pos->port == port) { vcpi = pos; prev_slots = vcpi->vcpi; + prev_bw = vcpi->pbn; /* * This should never happen, unless the driver tries @@ -4127,14 +4208,22 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, break; } } - if (!vcpi) + if (!vcpi) { prev_slots = 0; + prev_bw = 0; + } + + if (pbn_div <= 0) + pbn_div = mgr->pbn_div; - req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); + req_slots = DIV_ROUND_UP(pbn, pbn_div); DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n", port->connector->base.id, port->connector->name, port, prev_slots, req_slots); + DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", + port->connector->base.id, port->connector->name, + port, prev_bw, pbn); /* Add the new allocation to the state */ if (!vcpi) { @@ -4147,6 +4236,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, list_add(&vcpi->next, &topology_state->vcpis); } vcpi->vcpi = req_slots; + vcpi->pbn = pbn; return req_slots; } @@ -4397,10 +4487,11 @@ EXPORT_SYMBOL(drm_dp_check_act_status); * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. * @clock: dot clock for the mode * @bpp: bpp for the mode. + * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel * * This uses the formula in the spec to calculate the PBN value for a mode. */ -int drm_dp_calc_pbn_mode(int clock, int bpp) +int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) { /* * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 @@ -4411,7 +4502,16 @@ int drm_dp_calc_pbn_mode(int clock, int bpp) * peak_kbps *= (1006/1000) * peak_kbps *= (64/54) * peak_kbps *= 8 convert to bytes + * + * If the bpp is in units of 1/16, further divide by 16. Put this + * factor in the numerator rather than the denominator to avoid + * integer overflow */ + + if (dsc) + return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), + 8 * 54 * 1000 * 1000); + return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006), 8 * 54 * 1000 * 1000); } @@ -4713,9 +4813,61 @@ static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, kfree(mst_state); } +static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, + struct drm_dp_mst_branch *branch) +{ + while (port->parent) { + if (port->parent == branch) + return true; + + if (port->parent->port_parent) + port = port->parent->port_parent; + else + break; + } + return false; +} + +static inline +int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch, + struct drm_dp_mst_topology_state *mst_state) +{ + struct drm_dp_mst_port *port; + struct drm_dp_vcpi_allocation *vcpi; + int pbn_limit = 0, pbn_used = 0; + + list_for_each_entry(port, &branch->ports, next) { + if (port->mstb) + if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state)) + return -ENOSPC; + + if (port->available_pbn > 0) + pbn_limit = port->available_pbn; + } + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n", + branch, pbn_limit); + + list_for_each_entry(vcpi, &mst_state->vcpis, next) { + if (!vcpi->pbn) + continue; + + if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch)) + pbn_used += vcpi->pbn; + } + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n", + branch, pbn_used); + + if (pbn_used > pbn_limit) { + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n", + branch); + return -ENOSPC; + } + return 0; +} + static inline int -drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr, - struct drm_dp_mst_topology_state *mst_state) +drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_topology_state *mst_state) { struct drm_dp_vcpi_allocation *vcpi; int avail_slots = 63, payload_count = 0; @@ -4753,6 +4905,128 @@ drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr, } /** + * drm_dp_mst_add_affected_dsc_crtcs + * @state: Pointer to the new struct drm_dp_mst_topology_state + * @mgr: MST topology manager + * + * Whenever there is a change in mst topology + * DSC configuration would have to be recalculated + * therefore we need to trigger modeset on all affected + * CRTCs in that topology + * + * See also: + * drm_dp_mst_atomic_enable_dsc() + */ +int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) +{ + struct drm_dp_mst_topology_state *mst_state; + struct drm_dp_vcpi_allocation *pos; + struct drm_connector *connector; + struct drm_connector_state *conn_state; + struct drm_crtc *crtc; + struct drm_crtc_state *crtc_state; + + mst_state = drm_atomic_get_mst_topology_state(state, mgr); + + if (IS_ERR(mst_state)) + return -EINVAL; + + list_for_each_entry(pos, &mst_state->vcpis, next) { + + connector = pos->port->connector; + + if (!connector) + return -EINVAL; + + conn_state = drm_atomic_get_connector_state(state, connector); + + if (IS_ERR(conn_state)) + return PTR_ERR(conn_state); + + crtc = conn_state->crtc; + + if (WARN_ON(!crtc)) + return -EINVAL; + + if (!drm_dp_mst_dsc_aux_for_port(pos->port)) + continue; + + crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); + + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", + mgr, crtc); + + crtc_state->mode_changed = true; + } + return 0; +} +EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); + +/** + * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off + * @state: Pointer to the new drm_atomic_state + * @port: Pointer to the affected MST Port + * @pbn: Newly recalculated bw required for link with DSC enabled + * @pbn_div: Divider to calculate correct number of pbn per slot + * @enable: Boolean flag to enable or disable DSC on the port + * + * This function enables DSC on the given Port + * by recalculating its vcpi from pbn provided + * and sets dsc_enable flag to keep track of which + * ports have DSC enabled + * + */ +int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, + struct drm_dp_mst_port *port, + int pbn, int pbn_div, + bool enable) +{ + struct drm_dp_mst_topology_state *mst_state; + struct drm_dp_vcpi_allocation *pos; + bool found = false; + int vcpi = 0; + + mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); + + if (IS_ERR(mst_state)) + return PTR_ERR(mst_state); + + list_for_each_entry(pos, &mst_state->vcpis, next) { + if (pos->port == port) { + found = true; + break; + } + } + + if (!found) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n", + port, mst_state); + return -EINVAL; + } + + if (pos->dsc_enabled == enable) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n", + port, enable, pos->vcpi); + vcpi = pos->vcpi; + } + + if (enable) { + vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div); + DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n", + port, vcpi); + if (vcpi < 0) + return -EINVAL; + } + + pos->dsc_enabled = enable; + + return vcpi; +} +EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); +/** * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an * atomic update is valid * @state: Pointer to the new &struct drm_dp_mst_topology_state @@ -4780,7 +5054,13 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state) int i, ret = 0; for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { - ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state); + if (!mgr->mst_state) + continue; + + ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state); + if (ret) + break; + ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state); if (ret) break; } @@ -5044,3 +5324,173 @@ static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux) { 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); |