]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
Bluetooth: hci_h5: Complements reliable packet processing logic
authorQiqi Zhang <eddy.zhang@rock-chips.com>
Tue, 4 Apr 2023 02:27:11 +0000 (10:27 +0800)
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Mon, 24 Apr 2023 05:00:04 +0000 (22:00 -0700)
commit3c0d41f141c97e516d986f0571b0d7a745a4e2a8
tree115ce9d4ff759db3f134a048fd522646ad697af9
parent288c90224eec55d13e786844b7954ef060752089
Bluetooth: hci_h5: Complements reliable packet processing logic

As shown in the schematic diagram below.There may be a critical
scenario in the current code. If the device does not receive an
pure ack sent by the host due to insufficient receive buffer or
other reasons and triggers a retransmission, the host will always
be in an 'out-of-order' state.The state machine will get stuck.

       host                 device
     SEQ3,ACK4 --------->
               <--------- SEQ4,ACK4
     pure ACK  ---------> (not received)
(out-of-order) <--------- SEQ4,ACK4(retransmission)
                ........
(out-of-order) <--------- SEQ4,ACK4(retransmission)

According to the description in the core specification: "whenever
a reliable packet is received, an acknowledgment shall be generated."
So set H5_TX_ACK_REQ bit to trigger retransmission of pure ack packet
when "out-of-order" occurs.

Signed-off-by: Qiqi Zhang <eddy.zhang@rock-chips.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
drivers/bluetooth/hci_h5.c