Fixes to get HDCP2.2 over MST working on MST docking stations with certain behaviors that cause the current flow to fail. Tested with Dell WD-19 and Lenovo ThinkPad USB Type-C Dock Gen 2.
These fixes should make the flow more robust to handle behaviors that as far as I can tell are unclear in the HDCP spec:
RxInfo contains repeater topology information needed for MST. The behavior on these docks is that this can only be read during RepeaterAuth_Send_ReceiverID_List when the RxStatus READY bit is set otherwise the dock will return NACK. It seems these docks treat reading this range at any other time as invalid when the READY bit isn't set possibly because it could be stale. The HDCP spec also states the READY bit is cleared after RxInfo is read.
These fixes address this behavior by only reading RxInfo once during the AKE flow and reusing that data.
Changes since v1: - Fix subject line for 3/3
Juston Li (3): drm/i915/hdcp: update cp_irq_count_cached in intel_dp_hdcp2_read_msg() drm/i915/hdcp: read RxInfo once when reading RepeaterAuth_Send_ReceiverID_List drm/i915/hdcp: reuse rx_info for mst stream type1 capability check
.../drm/i915/display/intel_display_types.h | 2 + drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 77 +++++-------------- drivers/gpu/drm/i915/display/intel_hdcp.c | 47 +++++------ include/drm/drm_dp_helper.h | 2 +- 4 files changed, 43 insertions(+), 85 deletions(-)
Update cp_irq_count_cached when reading messages rather than when writing a message to make sure the value is up to date and not stale from a previously handled CP_IRQ.
AKE flow doesn't always respond to a read with a ACK write msg. E.g. AKE_Send_Pairing_Info will "timeout" because we received a CP_IRQ for reading AKE_Send_H_Prime but no write occurred between that and reading AKE_Send_Pairing_Info so cp_irq_count_cached is stale causing the wait to return right away rather than waiting for a new CP_IRQ.
Signed-off-by: Juston Li juston.li@intel.com Acked-by: Anshuman Gupta anshuman.gupta@intel.com --- drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c index d697d169e8c1..1d0096654776 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -446,8 +446,6 @@ static int intel_dp_hdcp2_write_msg(struct intel_digital_port *dig_port, void *buf, size_t size) { - struct intel_dp *dp = &dig_port->dp; - struct intel_hdcp *hdcp = &dp->attached_connector->hdcp; unsigned int offset; u8 *byte = buf; ssize_t ret, bytes_to_write, len; @@ -463,8 +461,6 @@ int intel_dp_hdcp2_write_msg(struct intel_digital_port *dig_port, bytes_to_write = size - 1; byte++;
- hdcp->cp_irq_count_cached = atomic_read(&hdcp->cp_irq_count); - while (bytes_to_write) { len = bytes_to_write > DP_AUX_MAX_PAYLOAD_BYTES ? DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_write; @@ -530,6 +526,8 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, u8 msg_id, void *buf, size_t size) { struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); + struct intel_dp *dp = &dig_port->dp; + struct intel_hdcp *hdcp = &dp->attached_connector->hdcp; unsigned int offset; u8 *byte = buf; ssize_t ret, bytes_to_recv, len; @@ -546,6 +544,8 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, if (ret < 0) return ret;
+ hdcp->cp_irq_count_cached = atomic_read(&hdcp->cp_irq_count); + if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST) { ret = get_receiver_id_list_size(dig_port); if (ret < 0)
When reading RepeaterAuth_Send_ReceiverID_List, RxInfo is read by itself once to retrieve the DEVICE_COUNT to calculate the size of the ReceiverID list then read a second time as a part of reading ReceiverID list.
On some MST docking stations, RxInfo can only be read after the RxStatus READY bit is set otherwise the read will return -EIO. The spec states that the READY bit should be cleared as soon as RxInfo has been read.
In this case, the first RxInfo read succeeds but after the READY bit is cleared, the second read fails.
Fix it by reading RxInfo once and storing it before reading the rest of RepeaterAuth_Send_ReceiverID_List once we know the size.
Modify get_receiver_id_list_size() to read and store RxInfo in the message buffer and also parse DEVICE_COUNT so we know the size of RepeaterAuth_Send_ReceiverID_List.
Afterwards, retrieve the rest of the message at the offset for seq_num_V.
Changes in v4: - rebase and edit commit message
Changes in v3: - remove comment
Changes in v2: - remove unnecessary moving of drm_i915_private from patch 1
Signed-off-by: Juston Li juston.li@intel.com Acked-by: Anshuman Gupta anshuman.gupta@intel.com --- drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 30 ++++++++++---------- include/drm/drm_dp_helper.h | 2 +- 2 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c index 1d0096654776..526fd58b9b51 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -496,11 +496,10 @@ get_rxinfo_hdcp_1_dev_downstream(struct intel_digital_port *dig_port, bool *hdcp }
static -ssize_t get_receiver_id_list_size(struct intel_digital_port *dig_port) +ssize_t get_receiver_id_list_rx_info(struct intel_digital_port *dig_port, u32 *dev_cnt, u8 *byte) { - u8 rx_info[HDCP_2_2_RXINFO_LEN]; - u32 dev_cnt; ssize_t ret; + u8 *rx_info = byte;
ret = drm_dp_dpcd_read(&dig_port->dp.aux, DP_HDCP_2_2_REG_RXINFO_OFFSET, @@ -508,15 +507,11 @@ ssize_t get_receiver_id_list_size(struct intel_digital_port *dig_port) if (ret != HDCP_2_2_RXINFO_LEN) return ret >= 0 ? -EIO : ret;
- dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 | + *dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 | HDCP_2_2_DEV_COUNT_LO(rx_info[1]));
- if (dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT) - dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT; - - ret = sizeof(struct hdcp2_rep_send_receiverid_list) - - HDCP_2_2_RECEIVER_IDS_MAX_LEN + - (dev_cnt * HDCP_2_2_RECEIVER_ID_LEN); + if (*dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT) + *dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT;
return ret; } @@ -534,6 +529,7 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, const struct hdcp2_dp_msg_data *hdcp2_msg_data; ktime_t msg_end = ktime_set(0, 0); bool msg_expired; + u32 dev_cnt;
hdcp2_msg_data = get_hdcp2_dp_msg_data(msg_id); if (!hdcp2_msg_data) @@ -546,17 +542,21 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port,
hdcp->cp_irq_count_cached = atomic_read(&hdcp->cp_irq_count);
+ /* DP adaptation msgs has no msg_id */ + byte++; + if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST) { - ret = get_receiver_id_list_size(dig_port); + ret = get_receiver_id_list_rx_info(dig_port, &dev_cnt, byte); if (ret < 0) return ret;
- size = ret; + byte += ret; + size = sizeof(struct hdcp2_rep_send_receiverid_list) - + HDCP_2_2_RXINFO_LEN - HDCP_2_2_RECEIVER_IDS_MAX_LEN + + (dev_cnt * HDCP_2_2_RECEIVER_ID_LEN); } - bytes_to_recv = size - 1;
- /* DP adaptation msgs has no msg_id */ - byte++; + bytes_to_recv = size - 1;
while (bytes_to_recv) { len = bytes_to_recv > DP_AUX_MAX_PAYLOAD_BYTES ? diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 3f2715eb965f..7476e7c6d0be 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1413,7 +1413,7 @@ enum drm_dp_phy { #define DP_HDCP_2_2_LC_INIT_OFFSET DP_HDCP_2_2_REG_RN_OFFSET #define DP_HDCP_2_2_LC_SEND_LPRIME_OFFSET DP_HDCP_2_2_REG_LPRIME_OFFSET #define DP_HDCP_2_2_SKE_SEND_EKS_OFFSET DP_HDCP_2_2_REG_EDKEY_KS_OFFSET -#define DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET DP_HDCP_2_2_REG_RXINFO_OFFSET +#define DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET DP_HDCP_2_2_REG_SEQ_NUM_V_OFFSET #define DP_HDCP_2_2_REP_SEND_ACK_OFFSET DP_HDCP_2_2_REG_V_OFFSET #define DP_HDCP_2_2_REP_STREAM_MANAGE_OFFSET DP_HDCP_2_2_REG_SEQ_NUM_M_OFFSET #define DP_HDCP_2_2_REP_STREAM_READY_OFFSET DP_HDCP_2_2_REG_MPRIME_OFFSET
On some MST docking stations, rx_info can only be read after RepeaterAuth_Send_ReceiverID_List and the RxStatus READY bit is set otherwise the read will return -EIO.
This behavior causes the mst stream type1 capability test to fail to read rx_info and determine if the topology supports type1 and fallback to type0.
To fix this, check for type1 capability when we receive rx_info within the AKE flow when we read RepeaterAuth_Send_ReceiverID_List instead of an explicit read just for type1 capability checking.
This does require moving where we set stream_types to after hdcp2_authenticate_sink() when we get rx_info but this occurs before we do hdcp2_propagate_stream_management_info.
Also, legacy HDCP 2.0/2.1 are not type 1 capable either so check for that as well.
Signed-off-by: Juston Li juston.li@intel.com --- .../drm/i915/display/intel_display_types.h | 2 + drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 39 --------------- drivers/gpu/drm/i915/display/intel_hdcp.c | 47 +++++++++---------- 3 files changed, 23 insertions(+), 65 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index dbdfe54d0340..c8b687ff0374 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -516,6 +516,8 @@ struct intel_hdcp { enum transcoder cpu_transcoder; /* Only used for DP MST stream encryption */ enum transcoder stream_transcoder; + + bool topology_type1_capable; };
struct intel_connector { diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c index 526fd58b9b51..2d39af63ec9b 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -478,23 +478,6 @@ int intel_dp_hdcp2_write_msg(struct intel_digital_port *dig_port, return size; }
-static int -get_rxinfo_hdcp_1_dev_downstream(struct intel_digital_port *dig_port, bool *hdcp_1_x) -{ - u8 rx_info[HDCP_2_2_RXINFO_LEN]; - int ret; - - ret = drm_dp_dpcd_read(&dig_port->dp.aux, - DP_HDCP_2_2_REG_RXINFO_OFFSET, - (void *)rx_info, HDCP_2_2_RXINFO_LEN); - - if (ret != HDCP_2_2_RXINFO_LEN) - return ret >= 0 ? -EIO : ret; - - *hdcp_1_x = HDCP_2_2_HDCP1_DEVICE_CONNECTED(rx_info[1]) ? true : false; - return 0; -} - static ssize_t get_receiver_id_list_rx_info(struct intel_digital_port *dig_port, u32 *dev_cnt, u8 *byte) { @@ -664,27 +647,6 @@ int intel_dp_hdcp2_capable(struct intel_digital_port *dig_port, return 0; }
-static -int intel_dp_mst_streams_type1_capable(struct intel_connector *connector, - bool *capable) -{ - struct intel_digital_port *dig_port = intel_attached_dig_port(connector); - struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); - int ret; - bool hdcp_1_x; - - ret = get_rxinfo_hdcp_1_dev_downstream(dig_port, &hdcp_1_x); - if (ret) { - drm_dbg_kms(&i915->drm, - "[%s:%d] failed to read RxInfo ret=%d\n", - connector->base.name, connector->base.base.id, ret); - return ret; - } - - *capable = !hdcp_1_x; - return 0; -} - static const struct intel_hdcp_shim intel_dp_hdcp_shim = { .write_an_aksv = intel_dp_hdcp_write_an_aksv, .read_bksv = intel_dp_hdcp_read_bksv, @@ -833,7 +795,6 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = { .stream_2_2_encryption = intel_dp_mst_hdcp2_stream_encryption, .check_2_2_link = intel_dp_mst_hdcp2_check_link, .hdcp_2_2_capable = intel_dp_hdcp2_capable, - .streams_type1_capable = intel_dp_mst_streams_type1_capable, .protocol = HDCP_PROTOCOL_DP, };
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index ebc2e32aec0b..fa6a60faa6a7 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -33,21 +33,6 @@ static int intel_conn_to_vcpi(struct intel_connector *connector) return connector->port ? connector->port->vcpi.vcpi : 0; }
-static bool -intel_streams_type1_capable(struct intel_connector *connector) -{ - const struct intel_hdcp_shim *shim = connector->hdcp.shim; - bool capable = false; - - if (!shim) - return capable; - - if (shim->streams_type1_capable) - shim->streams_type1_capable(connector, &capable); - - return capable; -} - /* * intel_hdcp_required_content_stream selects the most highest common possible HDCP * content_type for all streams in DP MST topology because security f/w doesn't @@ -86,7 +71,7 @@ intel_hdcp_required_content_stream(struct intel_digital_port *dig_port) if (conn_dig_port != dig_port) continue;
- if (!enforce_type0 && !intel_streams_type1_capable(connector)) + if (!enforce_type0 && !connector->hdcp.topology_type1_capable) enforce_type0 = true;
data->streams[data->k].stream_id = intel_conn_to_vcpi(connector); @@ -1632,6 +1617,14 @@ int hdcp2_authenticate_repeater_topology(struct intel_connector *connector) return -EINVAL; }
+ /* + * A topology is not Type 1 capable if it contains a downstream device + * that is HDCP 1.x or Legacy HDCP 2.0/2.1 compliant. + */ + hdcp->topology_type1_capable = + !HDCP_2_2_HDCP1_DEVICE_CONNECTED(rx_info[1]) && + !HDCP_2_2_HDCP_2_0_REP_CONNECTED(rx_info[1]); + /* Converting and Storing the seq_num_v to local variable as DWORD */ seq_num_v = drm_hdcp_be24_to_cpu((const u8 *)msgs.recvid_list.seq_num_v); @@ -1871,11 +1864,23 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector) { struct intel_digital_port *dig_port = intel_attached_dig_port(connector); struct drm_i915_private *i915 = to_i915(connector->base.dev); + struct hdcp_port_data *data = &dig_port->hdcp_port_data; + struct intel_hdcp *hdcp = &connector->hdcp; int ret = 0, i, tries = 3;
for (i = 0; i < tries && !dig_port->hdcp_auth_status; i++) { ret = hdcp2_authenticate_sink(connector); if (!ret) { + /* Stream which requires encryption */ + if (!intel_encoder_is_mst(intel_attached_encoder(connector))) { + data->k = 1; + data->streams[0].stream_type = hdcp->content_type; + } else { + ret = intel_hdcp_required_content_stream(dig_port); + if (ret) + return ret; + } + ret = hdcp2_propagate_stream_management_info(connector); if (ret) { drm_dbg_kms(&i915->drm, @@ -1931,16 +1936,6 @@ static int _intel_hdcp2_enable(struct intel_connector *connector) connector->base.name, connector->base.base.id, hdcp->content_type);
- /* Stream which requires encryption */ - if (!intel_encoder_is_mst(intel_attached_encoder(connector))) { - data->k = 1; - data->streams[0].stream_type = hdcp->content_type; - } else { - ret = intel_hdcp_required_content_stream(dig_port); - if (ret) - return ret; - } - ret = hdcp2_authenticate_and_encrypt(connector); if (ret) { drm_dbg_kms(&i915->drm, "HDCP2 Type%d Enabling Failed. (%d)\n",
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Juston Li