Bluetooth: Controller: BT_CTLR_ISO_TX_BUFFER_SIZE from BT_ISO_TX_MTU

Derive BT_CTLR_ISO_TX_BUFFER_SIZE from BT_ISO_TX_MTU to have
optimal Controller memory allocations.
BT_CTLR_ISO_TX_BUFFER_SIZE can be set lower than
BT_ISO_TX_MTU in which case upper layer can send fragmented
SDU to the Controller.

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>

Author: cvinayak

samples/bluetooth/broadcast_audio_source/overlay-bt_ll_sw_split.conf

@@ -14,11 +14,7 @@ CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=155
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
-# FIXME: Host needs CONFIG_BT_ISO_TX_MTU + 4 bytes for sequence number, and  optionally
-# additional + 4 bytes for timestamp when not using BT_ISO_TIMESTAMP_NONE in bt_iso_chan_send(),
-# otherwise Host tries to fragment ISO data.
-# When Host is fixed, CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE can inherit the
-# CONFIG_BT_ISO_TX_MTU value.
-#
-# Supports the highest SDU size required by any BAP LC3 presets (155)
+# Support the highest SDU size required by any BAP LC3 presets (155) + 8 bytes of HCI ISO Data
+# packet overhead (the Packet_Sequence_Number, ISO_SDU_Length, Packet_Status_Flag fields; and
+# the optional Time_Stamp field, if supplied)
 CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=163

samples/bluetooth/central_iso/overlay-bt_ll_sw_split.conf

@@ -0,0 +1,33 @@
+# Zephyr Bluetooth Controller
+CONFIG_BT_LL_SW_SPLIT=y
+
+# Zephyr Bluetooth LE Controller needs 16 event buffers to generate Extended
+# Advertising Report for receiving the complete 1650 bytes of data
+CONFIG_BT_BUF_EVT_RX_COUNT=16
+
+# Set maximum scan data length for Extended Scanning in Bluetooth LE Controller
+CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX=1650
+
+# Increase Zephyr Bluetooth LE Controller Rx buffer to receive complete chain
+# of PDUs
+CONFIG_BT_CTLR_RX_BUFFERS=9
+
+# Sufficient ISO SDU and PDU length for this sample with ISO_TX_MTU of 247
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
+CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
+
+# Number of supported streami sources and sinks
+CONFIG_BT_CTLR_ISOAL_SOURCES=2
+CONFIG_BT_CTLR_ISOAL_SINKS=1
+
+# Support the highest SDU size required by this sample 247 + 8 bytes of HCI ISO Data
+# packet overhead (timestamp and HCI ISO Data packet header)
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
+CONFIG_BT_CTLR_ISO_TX_BUFFERS=4
+
+# Use Low Latency Connected ISO policy
+CONFIG_BT_CTLR_ADVANCED_FEATURES=y
+CONFIG_BT_CTLR_CONN_ISO_LOW_LATENCY_POLICY=y
+
+# Use the below if the sample is sending stale packet sequence number
+# CONFIG_BT_CTLR_ISOAL_SN_STRICT=n

samples/bluetooth/central_iso/sample.yaml

@@ -8,3 +8,14 @@ tests:
     integration_platforms:
       - qemu_x86
     tags: bluetooth
+  sample.bluetooth.central_iso.bt_ll_sw_split:
+    harness: bluetooth
+    platform_allow:
+      - qemu_cortex_m3
+      - qemu_x86
+      - nrf52_bsim
+      - nrf52833dk/nrf52833
+    integration_platforms:
+      - nrf52833dk/nrf52833
+    extra_args: OVERLAY_CONFIG=overlay-bt_ll_sw_split.conf
+    tags: bluetooth

samples/bluetooth/hci_ipc/nrf5340_cpunet_bis-bt_ll_sw_split.conf

@@ -77,7 +77,7 @@ CONFIG_BT_CTLR_LLCP_LOCAL_PROC_CTX_BUF_NUM=6
 CONFIG_BT_CTLR_ADV_EXT=y
 CONFIG_BT_CTLR_ADV_PERIODIC=y
 CONFIG_BT_CTLR_ADV_ISO=y
-CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=251
+CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=247
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 
 # ISO Receive Controller
@@ -89,7 +89,7 @@ CONFIG_BT_CTLR_SYNC_ISO_STREAM_MAX=2
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions

samples/bluetooth/hci_ipc/nrf5340_cpunet_cis-bt_ll_sw_split.conf

@@ -77,12 +77,12 @@ CONFIG_BT_CTLR_LLCP_LOCAL_PROC_CTX_BUF_NUM=6
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=y
 CONFIG_BT_CTLR_PERIPHERAL_ISO=y
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions

samples/bluetooth/hci_ipc/nrf5340_cpunet_iso-bt_ll_sw_split.conf

@@ -82,7 +82,7 @@ CONFIG_BT_CTLR_LLCP_LOCAL_PROC_CTX_BUF_NUM=6
 CONFIG_BT_CTLR_ADV_EXT=y
 CONFIG_BT_CTLR_ADV_PERIODIC=y
 CONFIG_BT_CTLR_ADV_ISO=y
-CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=251
+CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=247
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 
 # ISO Receive Controller
@@ -95,12 +95,12 @@ CONFIG_BT_CTLR_SYNC_ISO_STREAM_MAX=2
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=y
 CONFIG_BT_CTLR_PERIPHERAL_ISO=y
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions

samples/bluetooth/hci_ipc/nrf5340_cpunet_iso_broadcast-bt_ll_sw_split.conf

@@ -31,8 +31,8 @@ CONFIG_BT_CTLR_ADV_PERIODIC=y
 CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=191
 CONFIG_BT_CTLR_ADV_ISO=y
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=16
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
-CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
+CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=247
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 

samples/bluetooth/hci_ipc/nrf5340_cpunet_iso_central-bt_ll_sw_split.conf

@@ -44,12 +44,12 @@ CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX=191
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=y
 CONFIG_BT_CTLR_PERIPHERAL_ISO=n
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=16
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions

samples/bluetooth/hci_ipc/nrf5340_cpunet_iso_peripheral-bt_ll_sw_split.conf

@@ -44,12 +44,12 @@ CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=191
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=n
 CONFIG_BT_CTLR_PERIPHERAL_ISO=y
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=16
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions

samples/bluetooth/hci_uart/overlay-all-bt_ll_sw_split.conf

@@ -80,7 +80,7 @@ CONFIG_BT_CTLR_DF_CONN_CTE_REQ=y
 CONFIG_BT_CTLR_ADV_EXT=y
 CONFIG_BT_CTLR_ADV_PERIODIC=y
 CONFIG_BT_CTLR_ADV_ISO=y
-CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=251
+CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=247
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 
 # ISO Receive Controller
@@ -93,12 +93,12 @@ CONFIG_BT_CTLR_SYNC_ISO_STREAM_MAX=2
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=y
 CONFIG_BT_CTLR_PERIPHERAL_ISO=y
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions