"Unable to allocate TX context" at the beginning of a stream

RE: "Unable to allocate TX context" at the beginning of a stream

mtsunstrum — Tue, 19 Apr 2022 17:07:30 GMT

OK, understood now.

Can you show a bit of code leading up to the bt_nus_send() area ?

Can you show the Peripheral logs showing connection negotiation, including the receiving the "go ahead" command from the Central, to a short time after the error logs you posted above?

Helpful if Peripheral outputs logs upon reception/confirmation of the above connection negotiations.

If you are using security/encryption, you may need to wait for that to complete also.

In Peripheral code, you should have callbacks for security_changed(), le_param_updated(), le_phy_updated(), le_data_length_updated()

I couldn't get a callback working for MTU update ( see atu_mtu_notification_callback() ), but you can print it out right after receiving your "go ahead" command from the Central. See bt_gatt_get_mtu(current_conn)

RE: "Unable to allocate TX context" at the beginning of a stream

Branislav — Tue, 19 Apr 2022 16:49:03 GMT

The peripheral is streaming the data, but it wont initiate the stream until central tells it to, and central is configured to send that command only after connection parameters are negotiated (+ some additional time)

RE: "Unable to allocate TX context" at the beginning of a stream

mtsunstrum — Tue, 19 Apr 2022 16:39:16 GMT

Hmmm ... who is streaming the data ... the central or the peripheral ? If the peripheral, then the waiting for end of connection negotiations should occur on the peripheral.

peripheral uses bt_nus_send(), whereas central uses bt_nus_client_send() ... so from your logs it seems that your Peripheral is streaming the data.

Do you have code on the peripheral side to ensure that you do not call bt_nus_send() until all negotiations are complete ? It would be helpful to paste some code to review.

RE: "Unable to allocate TX context" at the beginning of a stream

Branislav — Tue, 19 Apr 2022 12:52:04 GMT

Hi Amanda,

This is our prj.conf

CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y

CONFIG_HEAP_MEM_POOL_SIZE=2048

CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_APPEARANCE=833
CONFIG_BT_MAX_CONN=1
CONFIG_BT_MAX_PAIRED=1

CONFIG_BT_NUS=y

CONFIG_BT_SETTINGS=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
CONFIG_NVS=y
CONFIG_SETTINGS=y

CONFIG_DK_LIBRARY=y

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

CONFIG_LOG=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_BACKEND_UART=y

CONFIG_ASSERT=y

CONFIG_PWM=y
CONFIG_LED=y
CONFIG_LED_PWM=y
CONFIG_NRFX_PWM0=y
CONFIG_NRFX_PWM1=y
CONFIG_NRFX_PWM2=y
CONFIG_BT_USER_PHY_UPDATE=y
CONFIG_BT_USER_DATA_LEN_UPDATE=y

CONFIG_BT_USER_DATA_LEN_UPDATE=y
CONFIG_BT_USER_PHY_UPDATE=y
CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS=y

CONFIG_BT_DEVICE_NAME_DYNAMIC=y

CONFIG_BT_BUF_ACL_RX_SIZE=251
CONFIG_BT_ATT_PREPARE_COUNT=50
CONFIG_BT_L2CAP_TX_BUF_COUNT=20
CONFIG_BT_L2CAP_TX_MTU=247
CONFIG_BT_BUF_ACL_TX_COUNT=20
CONFIG_BT_BUF_ACL_TX_SIZE=251

CONFIG_NRFX_SPIM1=y
CONFIG_NRFX_SPIS2=y

And this is our hci_rpmsg.conf

CONFIG_RPMSG_SERVICE=y
CONFIG_RPMSG_SERVICE_MODE_REMOTE=y

CONFIG_HEAP_MEM_POOL_SIZE=8192

CONFIG_MAIN_STACK_SIZE=512
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512
CONFIG_BT=y
CONFIG_BT_HCI_RAW=y
CONFIG_BT_MAX_CONN=2
CONFIG_BT_HCI_RAW_RESERVE=1
CONFIG_BT_BUF_CMD_TX_COUNT=64

CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
CONFIG_BT_BUF_ACL_TX_SIZE=251
CONFIG_BT_BUF_ACL_RX_SIZE=502

CONFIG_SPEED_OPTIMIZATIONS=y

RE: "Unable to allocate TX context" at the beginning of a stream

Amanda Hsieh — Tue, 19 Apr 2022 12:48:19 GMT

Hi,

[quote user=""]

Connection parameters:

7.5ms Conn interval
1ms Slave latency
247 MTU
251 DLE
2M PHY

[/quote]

Could you share the prj.conf?

You also could refer to this setting https://github.com/nrfconnect/sdk-nrf/blob/main/samples/bluetooth/throughput/prj.conf.

Regards,
Amanda

RE: "Unable to allocate TX context" at the beginning of a stream

Branislav — Tue, 19 Apr 2022 09:56:52 GMT

That is not the case, on my central I await all of the connection paramater updates before proceeding with stream initiation.

To further test it out, I put a 5s delay in my central after negotiating the connection paramaters and the results are the same.

RE: "Unable to allocate TX context" at the beginning of a stream

mtsunstrum — Mon, 18 Apr 2022 23:24:40 GMT

After you establish a connection, then central and peripheral will start to negotiate the Connection parameters outlined above.

You should wait until this negotiation is finished before starting to send data. Note this can take upwards of 2-3 seconds.

Until such time, hold off on making calls to bt_nus_send()

RE: "Unable to allocate TX context" at the beginning of a stream

mtsunstrum — Mon, 18 Apr 2022 23:23:11 GMT

After you establish a connection, then central and peripheral will start to negotiate the Connection parameters outlined above.

You should wait until this negotiation is finished before starting to send data. Note this can take upwards of 2-3 seconds.

Until such time, hold off on making calls to bt_nus_send()