Hello,
I'm trying to configure a larger MTU because I need to read/write GATT characteristics with size 216. I've already tried setting CONFIG_BT_ATT_PREPARE_COUNT to allow "long writes", however, this is not a solution for me, because in this case Zephyr passes data blocks to my callback which are not necessarily a multiple of 4. I have this requirement because the data is directly forwarded to a DSP via SPI.
I found this answer and tried to do the same, however, I'm getting this error during configuration:
warning: attempt to assign the value '251' to the undefined symbol BT_BUF_ACL_RX_SIZE
The same is repeated for the TX setting. If I leave the two ACL settings out, I can build, but then writing the characteristic results in a timeout. I attached logging of the device at the bottom.
I can't find anything about these settings being renamed. What are the correct names of the settings to make this work?
[00:00:34.059,478] <dbg> bt_att.att_rsp_sent: conn 0x200020d8 chan 0x20009ee0 [00:00:34.059,509] <dbg> bt_att.att_sent: conn 0x200020d8 chan 0x20009ee8 [00:00:34.059,509] <dbg> bt_att.bt_att_sent: chan 0x20009ee0 [00:00:34.059,509] <dbg> bt_att.chan_rsp_sent: chan 0x20009ee0 [00:00:34.059,539] <dbg> bt_l2cap.bt_l2cap_recv: Packet for CID 4 len 7 [00:00:34.059,539] <dbg> bt_l2cap.l2cap_chan_recv: chan 0x20009ee8 len 7 [00:00:34.059,570] <dbg> bt_att.bt_att_recv: Received ATT chan 0x20009ee0 code 0x12 len 6 [00:00:34.059,570] <dbg> bt_att.att_write_req: handle 0x001a [00:00:34.059,631] <dbg> bt_att.write_cb: handle 0x001a offset 0 [00:00:34.062,622] <dbg> bt_att.bt_att_chan_send: chan 0x20009ee0 flags 1 code 0x13 [00:00:34.062,652] <dbg> bt_att.chan_send: code 0x13 [00:00:34.062,683] <dbg> bt_l2cap.bt_l2cap_send_cb: conn 0x200020d8 cid 4 len 1 [00:00:34.149,505] <dbg> bt_att.att_rsp_sent: conn 0x200020d8 chan 0x20009ee0 [00:00:34.149,536] <dbg> bt_att.att_sent: conn 0x200020d8 chan 0x20009ee8 [00:00:34.149,536] <dbg> bt_att.bt_att_sent: chan 0x20009ee0 [00:00:34.149,566] <dbg> bt_att.chan_rsp_sent: chan 0x20009ee0 [00:00:34.150,817] <err> bt_conn: Not enough buffer space for L2CAP data [00:00:34.151,489] <err> bt_conn: Unexpected L2CAP continuation [00:00:34.152,160] <err> bt_conn: Unexpected L2CAP continuation [00:00:34.152,832] <err> bt_conn: Unexpected L2CAP continuation [00:00:34.153,503] <err> bt_conn: Unexpected L2CAP continuation [00:00:34.154,174] <err> bt_conn: Unexpected L2CAP continuation [00:00:34.154,785] <err> bt_conn: Unexpected L2CAP continuation [00:01:04.208,953] <dbg> bt_l2cap.bt_l2cap_chan_del: conn 0x200020d8 chan 0x20009ee8 [00:01:04.208,953] <dbg> bt_att.bt_att_disconnected: chan 0x20009ee8 cid 0x0004 [00:01:04.208,984] <dbg> bt_att.att_chan_detach: chan 0x20009ee0 [00:01:04.209,014] <dbg> bt_gatt.bt_gatt_disconnected: conn 0x200020d8 [00:01:04.209,136] <dbg> bt_gatt.find_sc_cfg: id: 0, addr: f4:8c:50:08:fd:85 (public) [00:01:04.209,136] <dbg> bt_gatt.disconnected_cb: ccc 0x200006bc reseted [00:01:04.209,594] <dbg> bt_att.bt_att_released: chan 0x20009ee0 [00:01:04.209,594] <dbg> bt_l2cap.bt_l2cap_chan_del: conn 0x200020d8 chan 0x20002198 [00:01:04.209,625] <dbg> bt_l2cap.l2cap_disconnected: ch 0x20002198 cid 0x0005 [00:01:04.209,625] <dbg> bt_l2cap.bt_l2cap_chan_del: conn 0x200020d8 chan 0x200022e0
