The central_multilink sample issues various API calls
(in particular because it does some from the bt_workq("BT RX WQ"))
this results in a deadlock since there are not enough
HCI command buffers available, this is causing deadlocks on hardware
that do not support BT_HCI_ACL_FLOW_CONTROL.
Below is the flow where assert is observed:
bt_hci_le_enh_conn_complete() -> bt_conn_connected()
-> connected() callback -> start_scan() -> bt_le_scan_start()
-> set_random_address() -> bt_hci_cmd_send_sync: opcode 0x2005
-> Controller unresponsive, command opcode 0x2005 timeout with err -11
Since the start_scan is called from the callback and BT RX WQ thread,
the command buffers are still not available for the system work queue
to process the hci commands it has to send out for starting the scan.
By adding additional buffers this deadlock can be avoided.
Signed-off-by: Gudipudi Ramana Kumar <ragudipu@silabs.com>
Because the number of ACL RX buffers must be at least the number of
maximum connections plus one, increasing `CONFIG_BT_MAX_CONN` could
inadvertently lead to a build failure if the number of ACL RX buffers is
not also increased. This dependency may not be obvious to users.
To address this issue, this commit deprecates the
`CONFIG_BT_BUF_RX_COUNT` Kconfig symbol and computes the value in
`buf.h` using the new `BT_BUF_RX_COUNT` define. Note that the default
value and the minimum range value have been changed to 0 to "disable"
the option.
Additionally, to allow users to increase the number of ACL RX buffers,
this commit introduces the new `CONFIG_BT_BUF_RX_COUNT_EXTRA` Kconfig
symbol. The value of this symbol will be added to the computed value of
`BT_BUF_RX_COUNT`.
The configurations of tests and samples have been updated to reflect
these changes.
Signed-off-by: Théo Battrel <theo.battrel@nordicsemi.no>
Small update to have the central_multilink sample work correctly
with extended advertising (when enabled)
Signed-off-by: Troels Nilsson <trnn@demant.com>
Application demonstrating Bluetooth Low Energy Central role
functionality by scanning for other devices and establishing
connection to upto 62 peripherals with a strong enough
signal.
Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>
