drm/amd/display: determine rx id list bytes to read based on device count

[why]
Some RX doesn't like us to read rx id list upto max rx id list size.  As
discussed, we decided to read rx id list based on device count.

[how]
According to HDCP specs the actual size of rx id list is calculated as
rx id list size = 2+3+16+5*device_count.  We will read 16 bytes at a
time until it reached or exceeded rx id list size.
Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Ashley Thomas <Ashley.Thomas2@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c

@@ -65,6 +65,7 @@ enum mod_hdcp_ddc_message_id {
 	MOD_HDCP_MESSAGE_ID_READ_LC_SEND_L_PRIME,
 	MOD_HDCP_MESSAGE_ID_WRITE_SKE_SEND_EKS,
 	MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST,
+	MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST_PART2,
 	MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_SEND_ACK,
 	MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_STREAM_MANAGE,
 	MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_STREAM_READY,
@@ -101,6 +102,7 @@ static const uint8_t hdcp_i2c_offsets[] = {
 	[MOD_HDCP_MESSAGE_ID_READ_LC_SEND_L_PRIME] = 0x80,
 	[MOD_HDCP_MESSAGE_ID_WRITE_SKE_SEND_EKS] = 0x60,
 	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST] = 0x80,
+	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST_PART2] = 0x80,
 	[MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_SEND_ACK] = 0x60,
 	[MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_STREAM_MANAGE] = 0x60,
 	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_STREAM_READY] = 0x80,
@@ -135,6 +137,7 @@ static const uint32_t hdcp_dpcd_addrs[] = {
 	[MOD_HDCP_MESSAGE_ID_READ_LC_SEND_L_PRIME] = 0x692f8,
 	[MOD_HDCP_MESSAGE_ID_WRITE_SKE_SEND_EKS] = 0x69318,
 	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST] = 0x69330,
+	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST_PART2] = 0x69340,
 	[MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_SEND_ACK] = 0x693e0,
 	[MOD_HDCP_MESSAGE_ID_WRITE_REPEATER_AUTH_STREAM_MANAGE] = 0x693f0,
 	[MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_STREAM_READY] = 0x69473,
@@ -474,14 +477,27 @@ enum mod_hdcp_status mod_hdcp_read_l_prime(struct mod_hdcp *hdcp)
 
 enum mod_hdcp_status mod_hdcp_read_rx_id_list(struct mod_hdcp *hdcp)
 {
-	enum mod_hdcp_status status;
+	enum mod_hdcp_status status = MOD_HDCP_STATUS_SUCCESS;
 
 	if (is_dp_hdcp(hdcp)) {
+		uint32_t device_count = 0;
+		uint32_t rx_id_list_size = 0;
+		uint32_t bytes_read = 0;
+
 		hdcp->auth.msg.hdcp2.rx_id_list[0] = 12;
 		status = read(hdcp, MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST,
-				hdcp->auth.msg.hdcp2.rx_id_list+1,
-				sizeof(hdcp->auth.msg.hdcp2.rx_id_list)-1);
-
+						hdcp->auth.msg.hdcp2.rx_id_list+1,
+						HDCP_MAX_AUX_TRANSACTION_SIZE);
+		if (status == MOD_HDCP_STATUS_SUCCESS) {
+			bytes_read = HDCP_MAX_AUX_TRANSACTION_SIZE;
+			device_count = HDCP_2_2_DEV_COUNT_LO(hdcp->auth.msg.hdcp2.rx_id_list[2]) +
+					(HDCP_2_2_DEV_COUNT_HI(hdcp->auth.msg.hdcp2.rx_id_list[1]) << 4);
+			rx_id_list_size = MIN((21 + 5 * device_count),
+					(sizeof(hdcp->auth.msg.hdcp2.rx_id_list) - 1));
+			status = read(hdcp, MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST_PART2,
+					hdcp->auth.msg.hdcp2.rx_id_list + 1 + bytes_read,
+					(rx_id_list_size - 1) / HDCP_MAX_AUX_TRANSACTION_SIZE * HDCP_MAX_AUX_TRANSACTION_SIZE);
+		}
 	} else {
 		status = read(hdcp, MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST,
 				hdcp->auth.msg.hdcp2.rx_id_list,