Hi Gustavo,
>>> Even though the HCI_Delete_Stored_Link_Key command is mandatory for 1.1
>>> and later controllers some controllers do not seem to support it
>>> properly as was witnessed by one Broadcom based controller:
>>>
>>> < HCI Command: Delete Stored Link Key (0x03|0x0012) plen 7
>>> bdaddr 00:00:00:00:00:00 all 1
>>>> HCI Event: Command Complete (0x0e) plen 4
>>> Delete Stored Link Key (0x03|0x0012) ncmd 1
>>> status 0x11 deleted 0
>>> Error: Unsupported Feature or Parameter Value
>>>
>>> Luckily this same controller also doesn't list the command in its
>>> supported commands bit mask (counting from 0 bit 7 of octet 6):
>>>
>>> < HCI Command: Read Local Supported Commands (0x04|0x0002) plen 0
>>>> HCI Event: Command Complete (0x0e) plen 68
>>> Read Local Supported Commands (0x04|0x0002) ncmd 1
>>> status 0x00
>>> Commands: ffffffffffff1ffffffffffff30fffff3f
>>>
>>> Therefore, it makes sense to move sending of HCI_Delete_Stored_Link_Key
>>> to after receiving the supported commands response and to only send it
>>> if its respective bit in the mask is set. The downside of this is that
>>> we no longer send the HCI_Delete_Stored_Link_Key command for Bluetooth
>>> 1.1 controllers since HCI_Read_Local_Supported_Command was introduced in
>>> version 1.2, but this is an acceptable penalty as the command in
>>> question shouldn't affect critical behavior.
>>>
>>> Reported-by: Pavel Machek <pavel@xxxxxx>
>>> Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
>>> ---
>>> net/bluetooth/hci_core.c | 14 +++++++++-----
>>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
>>> index d817c93..d68425c 100644
>>> --- a/net/bluetooth/hci_core.c
>>> +++ b/net/bluetooth/hci_core.c
>>> @@ -341,7 +341,6 @@ static void hci_init1_req(struct hci_request *req, unsigned long opt)
>>>
>>> static void bredr_setup(struct hci_request *req)
>>> {
>>> - struct hci_cp_delete_stored_link_key cp;
>>> __le16 param;
>>> __u8 flt_type;
>>>
>>> @@ -365,10 +364,6 @@ static void bredr_setup(struct hci_request *req)
>>> param = __constant_cpu_to_le16(0x7d00);
>>> hci_req_add(req, HCI_OP_WRITE_CA_TIMEOUT, 2, ¶m);
>>>
>>> - bacpy(&cp.bdaddr, BDADDR_ANY);
>>> - cp.delete_all = 0x01;
>>> - hci_req_add(req, HCI_OP_DELETE_STORED_LINK_KEY, sizeof(cp), &cp);
>>> -
>>> /* Read page scan parameters */
>>> if (req->hdev->hci_ver > BLUETOOTH_VER_1_1) {
>>> hci_req_add(req, HCI_OP_READ_PAGE_SCAN_ACTIVITY, 0, NULL);
>>> @@ -602,6 +597,15 @@ static void hci_init3_req(struct hci_request *req, unsigned long opt)
>>> struct hci_dev *hdev = req->hdev;
>>> u8 p;
>>
>> I would have added here a comment to explain what bit we are checking for.
>
> I just added:
>
> /* Only send HCI_Delete_Stored_Link_Key if it is supported */
that is the super cheap way out. There is no harm in going into details.
/* Some Broadcom based Bluetooth controllers do not support the
* Delete Stored Link Key command. They are clearly indicating its
* absence in the bit mask of supported commands.
*
* Check the supported commands and only if the the command is marked as
* supported send it. If not supported assume that the controller does not
* have actual support for stored link keys which makes this command
* redundant anyway.
*/
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
