Hi Mat, > The previous value of 672 for L2CAP_DEFAULT_MAX_PDU_SIZE is based on > the default L2CAP MTU. That default MTU is calculated from the size > of two DH5 packets, minus ACL and L2CAP b-frame header overhead. > > ERTM is used with newer basebands that typically support larger 3-DH5 > packets, and i-frames and s-frames have more header overhead. With > clean RF conditions, basebands will typically attempt to use 1021-byte > 3-DH5 packets for maximum throughput. Adjusting for 2 bytes of ACL > headers plus 10 bytes of worst-case L2CAP headers yields 1009 bytes > of payload. > > This PDU size imposes less overhead for header bytes and gives the > baseband the option to choose 3-DH5 packets, but is small enough for > ERTM traffic to interleave well with other L2CAP or SCO data. > 672-byte payloads do not allow the most efficient over-the-air > packet choice, and cannot achieve maximum throughput over BR/EDR. > > Signed-off-by: Mat Martineau <mathewm@xxxxxxxxxxxxxx> > --- > include/net/bluetooth/l2cap.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) patch has been applied. Thanks. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
