linux/include/net/bluetooth, branch v2.6.36

Bluetooth: Fix deadlock in the ERTM logic

2010-09-30T15:19:35Z

The Enhanced Retransmission Mode(ERTM) is a realiable mode of operation of the Bluetooth L2CAP layer. Think on it like a simplified version of TCP. The problem we were facing here was a deadlock. ERTM uses a backlog queue to queue incomimg packets while the user is helding the lock. At some moment the sk_sndbuf can be exceeded and we can't alloc new skbs then the code sleep with the lock to wait for memory, that stalls the ERTM connection once we can't read the acknowledgements packets in the backlog queue to free memory and make the allocation of outcoming skb successful. This patch actually affect all users of bt_skb_send_alloc(), i.e., all L2CAP modes and SCO. We are safe against socket states changes or channels deletion while the we are sleeping wait memory. Checking for the sk->sk_err and sk->sk_shutdown make the code safe, since any action that can leave the socket or the channel in a not usable state set one of the struct members at least. Then we can check both of them when getting the lock again and return with the proper error if something unexpected happens. Signed-off-by: Gustavo F. Padovan Signed-off-by: Ulisses Furquim

Bluetooth: Use 3-DH5 payload size for default ERTM max PDU size

2010-08-10T11:59:11Z

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 Signed-off-by: Marcel Holtmann

Bluetooth: Change default L2CAP ERTM retransmit timeout

2010-08-10T11:59:11Z

The L2CAP specification requires that the ERTM retransmit timeout be at least 2 seconds for BR/EDR connections. Signed-off-by: Mat Martineau Signed-off-by: Marcel Holtmann

Bluetooth: Use list_head for HCI blacklist head

2010-07-31T23:06:58Z

The bdaddr in the list root is completely unused and just taking up space. Signed-off-by: David S. Miller Tested-by: Johan Hedberg Signed-off-by: Marcel Holtmann

Bluetooth: Defer SCO setup if mode change is pending

2010-07-27T19:29:04Z

Certain headsets such as the Motorola H350 will reject SCO and eSCO connection requests while the ACL is transitioning from sniff mode to active mode. Add synchronization so that SCO and eSCO connection requests will wait until the ACL has fully transitioned to active mode. < HCI Command: Exit Sniff Mode (0x02|0x0004) plen 2 handle 12 > HCI Event: Command Status (0x0f) plen 4 Exit Sniff Mode (0x02|0x0004) status 0x00 ncmd 1 < HCI Command: Setup Synchronous Connection (0x01|0x0028) plen 17 handle 12 voice setting 0x0040 > HCI Event: Command Status (0x0f) plen 4 Setup Synchronous Connection (0x01|0x0028) status 0x00 ncmd 1 > HCI Event: Number of Completed Packets (0x13) plen 5 handle 12 packets 1 > HCI Event: Mode Change (0x14) plen 6 status 0x00 handle 12 mode 0x00 interval 0 Mode: Active > HCI Event: Synchronous Connect Complete (0x2c) plen 17 status 0x10 handle 14 bdaddr 00:1A:0E:50:28:A4 type SCO Error: Connection Accept Timeout Exceeded Signed-off-by: Ron Shaffer Signed-off-by: Marcel Holtmann

Bluetooth: Use __packed annotation

2010-07-21T17:39:13Z

To make net/ and include/net/ code consistent use __packed instead of __attribute__ ((packed)). Bluetooth subsystem was one of the last net subsys still using __attribute__ ((packed)). Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann

Bluetooth: Add Google's copyright to L2CAP

2010-07-21T17:39:12Z

Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann

Bluetooth: Implemented HCI frame reassembly for RX from stream

2010-07-21T17:39:12Z

Implemented frame reassembly implementation for reassembling fragments received from stream. Signed-off-by: Suraj Sumangala Signed-off-by: Marcel Holtmann

Bluetooth: Implement hci_reassembly helper to reassemble RX packets

2010-07-21T17:39:12Z

Implements feature to reassemble received HCI frames from any input stream Signed-off-by: Suraj Sumangala Signed-off-by: Marcel Holtmann

Bluetooth: Add one more buffer for HCI stream reassembly

2010-07-21T17:39:12Z

Additional reassembly buffer to keep track of stream reasembly Signed-off-by: Suraj Sumangala Signed-off-by: Marcel Holtmann