Unable to allocate TX context.

[xinjiang]

I made a custom model under ncs1.6.0 to publish uart data. When the data I want to publish exceeds 85 bytes, an error occurs in debug: 

<err> bt_conn: Unable to allocate TX context

model publish function, at this time datalen is 87:

The specific error is that the tx of the bt_conn_send_cb function in connc.c is NULL.

But in mesh, the maximum data length allowed to be sent is 380 bytes. I don’t know if it is caused by insufficient memory. Can you help me analyze the reason why tx is NULL?

...

[Amanda Hsieh]

Hi, 

Please check the value of these settings in prj.conf : `CONFIG_BT_MESH_TX_SEG_MAX` (on the transmitter side) and `CONFIG_BT_MESH_RX_SEG_MAX` on the receiver side. These should be set to 32 to support the maximum length of an access message.

-Amanda H.