Hi,
I have noticed with 2.6.27 that a bluez receiving side of l2ping will
detch the ACL connection (preventing further l2cap echos) after 10
seconds. HCI log below.
Is this by design, or was it unintentional?
I notice the OSX stack will detach after 60 seconds, so maybe it is by
design, after all the receiving side may not want to deal with these
unsolicited pings forever. In that case do you know the right place to
revert this behavior (l2ping is useful for testing).
Nick
2008-11-25 17:32:06.310607 > HCI Event: Connect Request (0x04) plen 10
bdaddr 00:17:E8:2E:6B:E3 class 0x00020c type ACL
2008-11-25 17:32:06.310821 < HCI Command: Accept Connection Request
(0x01|0x0009) plen 7
bdaddr 00:17:E8:2E:6B:E3 role 0x00
Role: Master
2008-11-25 17:32:06.315826 > HCI Event: Command Status (0x0f) plen 4
Accept Connection Request (0x01|0x0009) status 0x00 ncmd 1
2008-11-25 17:32:06.484832 > HCI Event: Role Change (0x12) plen 8
status 0x00 bdaddr 00:17:E8:2E:6B:E3 role 0x00
Role: Master
2008-11-25 17:32:06.517578 > HCI Event: Connect Complete (0x03) plen 11
status 0x00 handle 1 bdaddr 00:17:E8:2E:6B:E3 type ACL encrypt 0x00
2008-11-25 17:32:06.517639 > HCI Event: Page Scan Repetition Mode
Change (0x20) plen 7
bdaddr 00:17:E8:2E:6B:E3 mode 1
2008-11-25 17:32:06.517883 < HCI Command: Read Remote Supported
Features (0x01|0x001b) plen 2
handle 1
2008-11-25 17:32:06.523284 > HCI Event: Command Status (0x0f) plen 4
Read Remote Supported Features (0x01|0x001b) status 0x00 ncmd 1
2008-11-25 17:32:06.530517 > HCI Event: Max Slots Change (0x1b) plen 3
handle 1 slots 5
2008-11-25 17:32:06.530548 > ACL data: handle 1 flags 0x02 dlen 10
L2CAP(s): Info req: type 2
2008-11-25 17:32:06.530670 < ACL data: handle 1 flags 0x02 dlen 16
L2CAP(s): Info rsp: type 2 result 0
Extended feature mask 0x0000
2008-11-25 17:32:06.540283 < HCI Command: Remote Name Request
(0x01|0x0019) plen 10
bdaddr 00:17:E8:2E:6B:E3 mode 2 clkoffset 0x0000
2008-11-25 17:32:06.545532 > HCI Event: Command Status (0x0f) plen 4
Remote Name Request (0x01|0x0019) status 0x00 ncmd 1
2008-11-25 17:32:06.577911 > HCI Event: Read Remote Supported Features
(0x0b) plen 11
status 0x00 handle 1
Features: 0xff 0xff 0x2d 0xfe 0x9b 0xf9 0x00 0x80
2008-11-25 17:32:06.577941 > HCI Event: Remote Name Req Complete (0x07) plen 255
status 0x00 bdaddr 00:17:E8:2E:6B:E3 name 'dream'
2008-11-25 17:32:06.577941 > HCI Event: Number of Completed Packets
(0x13) plen 5
handle 1 packets 1
2008-11-25 17:32:06.610351 > ACL data: handle 1 flags 0x02 dlen 52
L2CAP(s): Echo req: dlen 44
0000: 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f 50 ABCDEFGHIJKLMNOP
0010: 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 60 QRSTUVWXYZ[\]^_`
0020: 61 62 63 64 65 66 67 68 41 42 43 44 abcdefghABCD
2008-11-25 17:32:06.610504 < ACL data: handle 1 flags 0x02 dlen 52
L2CAP(s): Echo rsp: dlen 44
0000: 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f 50 ABCDEFGHIJKLMNOP
0010: 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 60 QRSTUVWXYZ[\]^_`
0020: 61 62 63 64 65 66 67 68 41 42 43 44 abcdefghABCD
2008-11-25 17:32:06.622192 > HCI Event: Number of Completed Packets
(0x13) plen 5
handle 1 packets 1
[ 10 seconds ]
2008-11-25 17:32:16.169464 > ACL data: handle 1 flags 0x02 dlen 52
L2CAP(s): Echo req: dlen 44
0000: 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f 50 ABCDEFGHIJKLMNOP
0010: 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 60 QRSTUVWXYZ[\]^_`
0020: 61 62 63 64 65 66 67 68 41 42 43 44 abcdefghABCD
2008-11-25 17:32:16.169616 < ACL data: handle 1 flags 0x02 dlen 52
L2CAP(s): Echo rsp: dlen 44
0000: 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f 50 ABCDEFGHIJKLMNOP
0010: 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f 60 QRSTUVWXYZ[\]^_`
0020: 61 62 63 64 65 66 67 68 41 42 43 44 abcdefghABCD
2008-11-25 17:32:16.183380 > HCI Event: Number of Completed Packets
(0x13) plen 5
handle 1 packets 1
2008-11-25 17:32:16.576141 < HCI Command: Disconnect (0x01|0x0006) plen 3
handle 1 reason 0x13
Reason: Remote User Terminated Connection
2008-11-25 17:32:16.589813 > HCI Event: Command Status (0x0f) plen 4
Disconnect (0x01|0x0006) status 0x00 ncmd 1
2008-11-25 17:32:16.589843 > HCI Event: Disconn Complete (0x05) plen 4
status 0x00 handle 1 reason 0x16
Reason: Connection Terminated by Local Host
On Tue, Nov 25, 2008 at 9:00 PM, Marcel Holtmann <[email protected]> wrote:
> Hi Nick,
>
>> I have noticed with 2.6.27 that a bluez receiving side of l2ping will
>> detch the ACL connection (preventing further l2cap echos) after 10
>> seconds. HCI log below.
>>
>> Is this by design, or was it unintentional?
>
> it is not fully intentional, but it result due the fact on how we had to
> implement the Simple Pairing support. Problem here is that l2ping can not
> create a remote reference count of the connection. So BlueZ will clean up
> the ACL link. And we do have to do that since otherwise we waste power with
> an unused link.
Yeah I think it is an ok policy, like you say its bad for power to
maintain to link with no local client using it.
> So if you do l2test -P 1 -n <bdaddr> first and then l2ping you will see that
> the ACL link stays up since the l2test hold a remote reference count.
Ok, that'll do for a workaround for testing.
By the way, what happened to the HCI_UART_DEBUG patch I sent a few days ago?
Thanks,
Nick
Hi Nick,
> I have noticed with 2.6.27 that a bluez receiving side of l2ping will
> detch the ACL connection (preventing further l2cap echos) after 10
> seconds. HCI log below.
>
> Is this by design, or was it unintentional?
it is not fully intentional, but it result due the fact on how we had
to implement the Simple Pairing support. Problem here is that l2ping
can not create a remote reference count of the connection. So BlueZ
will clean up the ACL link. And we do have to do that since otherwise
we waste power with an unused link.
So if you do l2test -P 1 -n <bdaddr> first and then l2ping you will
see that the ACL link stays up since the l2test hold a remote
reference count.
Regards
Marcel