Hi Jaganath, > Some faulty non ssp devices send extended inquiry response can we either spell out SSP or have it upper case here. > during device discovery which is a violation of 2.1 specification. > So for these devices we set ssp bit during acl connection > initiation thinking that it is an ssp device. But for these > devices, in remote extended features event ssp supported bit > will be off. But we are not clearing the ssp bit in that case > and eventually ssp bit in conn flag will be incorrectly set for > these devices. > > The software which has caused this issue is MecApp > http://www.mecel.se/products/bluetooth/downloads/MecApp_download > > This patch does a workaround by clearing the ssp bit if it is > not supported in remote extended features event The features page is actually the remote host features. > > hcidump log > ---------- > > < HCI Command: Inquiry (0x01|0x0001) plen 5 > lap 0x9e8b33 len 4 num 0 >> HCI Event: Command Status (0x0f) plen 4 > Inquiry (0x01|0x0001) status 0x00 ncmd 1 >> HCI Event: Extended Inquiry Result (0x2f) plen 255 > bdaddr 00:1B:DC:05:B5:25 mode 1 clkoffset 0x3263 class 0x3c0000 rssi -77 > Unknown type 0x42 with 8 bytes data > Unknown type 0x1e with 2 bytes data >> HCI Event: Inquiry Complete (0x01) plen 1 > status 0x00 > > < HCI Command: Create Connection (0x01|0x0005) plen 13 > bdaddr 00:1B:DC:05:B5:25 ptype 0xcc18 rswitch 0x01 clkoffset 0x0000 > Packet type: DM1 DM3 DM5 DH1 DH3 DH5 >> HCI Event: Command Status (0x0f) plen 4 > Create Connection (0x01|0x0005) status 0x00 ncmd 1 >> HCI Event: Connect Complete (0x03) plen 11 > status 0x00 handle 12 bdaddr 00:1B:DC:05:B5:25 type ACL encrypt 0x00 > < HCI Command: Read Remote Supported Features (0x01|0x001b) plen 2 > handle 12 >> HCI Event: Command Status (0x0f) plen 4 > Read Remote Supported Features (0x01|0x001b) status 0x00 ncmd 1 >> HCI Event: Read Remote Supported Features (0x0b) plen 11 > status 0x00 handle 12 > Features: 0xff 0xff 0x8f 0x7e 0xd8 0x1f 0x5b 0x87 > < HCI Command: Read Remote Extended Features (0x01|0x001c) plen 3 > handle 12 page 1 >> HCI Event: Command Status (0x0f) plen 4 > Read Remote Extended Features (0x01|0x001c) status 0x00 ncmd 1 >> HCI Event: Page Scan Repetition Mode Change (0x20) plen 7 > bdaddr 00:1B:DC:05:B5:25 mode 1 >> HCI Event: Max Slots Change (0x1b) plen 3 > handle 12 slots 5 >> HCI Event: Read Remote Extended Features (0x23) plen 13 > status 0x00 handle 12 page 1 max 0 > Features: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 > < HCI Command: Remote Name Request (0x01|0x0019) plen 10 > bdaddr 00:1B:DC:05:B5:25 mode 2 clkoffset 0x0000 >> HCI Event: Command Status (0x0f) plen 4 > Remote Name Request (0x01|0x0019) status 0x00 ncmd 1 >> HCI Event: Remote Name Req Complete (0x07) plen 255 > status 0x00 bdaddr 00:1B:DC:05:B5:25 name 'Bluetooth PTS Radio v4' > < HCI Command: Authentication Requested (0x01|0x0011) plen 2 > handle 12 >> HCI Event: Command Status (0x0f) plen 4 > Authentication Requested (0x01|0x0011) status 0x00 ncmd 1 >> HCI Event: Link Key Request (0x17) plen 6 > bdaddr 00:1B:DC:05:B5:25 > < HCI Command: Link Key Request Negative Reply (0x01|0x000c) plen 6 > bdaddr 00:1B:DC:05:B5:25 >> HCI Event: Command Complete (0x0e) plen 10 > Link Key Request Negative Reply (0x01|0x000c) ncmd 1 > status 0x00 bdaddr 00:1B:DC:05:B5:25 >> HCI Event: PIN Code Request (0x16) plen 6 > bdaddr 00:1B:DC:05:B5:25 > > Signed-off-by: Jaganath Kanakkassery <jaganath.k@xxxxxxxxxxx> > --- > net/bluetooth/hci_event.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index 0a2b128..838ef5c 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -2933,8 +2933,13 @@ static void hci_remote_ext_features_evt(struct hci_dev *hdev, > if (ie) > ie->data.ssp_mode = (ev->features[0] & LMP_HOST_SSP); > > - if (ev->features[0] & LMP_HOST_SSP) > + if (ev->features[0] & LMP_HOST_SSP) { > set_bit(HCI_CONN_SSP_ENABLED, &conn->flags); > + } else { > + /* This is a workaround for some devices which send eir > + * which actually does not support ssp */ > + clear_bit(HCI_CONN_SSP_ENABLED, &conn->flags); This is actually not phrased correctly. /* It is mandatory by the Bluetooth specification that Extended Inquiry * Results are only used when Secure Simple Pairing is enabled, but some * devices violate this. * * To make these devices work, the internal SSP enabled flag needs to be * cleared if the remote host features do not indicate SSP support */ Comments are here to give a clear understanding why things are done. If the comment is even more cryptic, then that is not helpful. So please be descriptive. 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
