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authorMarcel Holtmann <marcel@holtmann.org>2013-10-23 08:28:01 -0700
committerGustavo Padovan <gustavo.padovan@collabora.co.uk>2013-12-04 11:09:02 -0200
commit33337dcb891e54d63433101af21fbff0b3f87bfa (patch)
tree1e7b0d93108e844e7d0ae18b244456649cc02d65
parent4b074b07625f603d40d4d04937f8874a00415dc4 (diff)
downloadlinux-33337dcb891e54d63433101af21fbff0b3f87bfa.tar.bz2
Bluetooth: Fix limited discoverable mode for Zeevo modules
There is an old Panasonic module with a Zeevo chip in there that is not really operating according to Bluetooth core specification when it comes to setting the IAC LAP for limited discoverable mode. For reference, this is the vendor information about this module: < HCI Command: Read Local Version Information (0x04|0x0001) plen 0 > HCI Event: Command Complete (0x0e) plen 12 Read Local Version Information (0x04|0x0001) ncmd 1 Status: Success (0x00) HCI version: Bluetooth 1.2 (0x02) - Revision 196 (0x00c4) LMP version: Bluetooth 1.2 (0x02) - Subversion 61 (0x003d) Manufacturer: Zeevo, Inc. (18) The module reports only the support for one IAC at a time. And that is totally acceptable according to the Bluetooth core specification since the minimum supported IAC is only one. < HCI Command: Read Number of Supported IAC (0x03|0x0038) plen 0 > HCI Event: Command Complete (0x0e) plen 5 Read Number of Supported IAC (0x03|0x0038) ncmd 1 Status: Success (0x00) Number of IAC: 1 The problem arises when trying to program two IAC into the module on a controller that only supports one. < HCI Command: Write Current IAC LAP (0x03|0x003a) plen 7 Number of IAC: 2 Access code: 0x9e8b00 (Limited Inquiry) Access code: 0x9e8b33 (General Inquiry) > HCI Event: Command Status (0x0f) plen 4 Write Current IAC LAP (0x03|0x003a) ncmd 1 Status: Unknown HCI Command (0x01) While this looks strange, but according to the Bluetooth core specification it is a legal operation. The controller has to ignore the other values and only program as many as it supports. This command shall clear any existing IACs and stores Num_Current_IAC and the IAC_LAPs in to the controller. If Num_Current_IAC is greater than Num_Support_IAC then only the first Num_Support_IAC shall be stored in the controller, and a Command Complete event with error code Success (0x00) shall be generated. This specific controller has a bug here and just returns an error. So in case the number of supported IAC is less than two and the limited discoverable mode is requested, now only the LIAC is written to the controller. < HCI Command: Write Current IAC LAP (0x03|0x003a) plen 4 Number of IAC: 1 Access code: 0x9e8b00 (Limited Inquiry) > HCI Event: Command Complete (0x0e) plen 4 Write Current IAC LAP (0x03|0x003a) ncmd 1 Status: Success (0x00) All other controllers that only support one IAC seem to handle this perfectly fine, but this fix will only write the LIAC for these controllers as well. Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
-rw-r--r--net/bluetooth/mgmt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 074d83690a41..22cf54710744 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1264,7 +1264,7 @@ static int set_discoverable(struct sock *sk, struct hci_dev *hdev, void *data,
if (cp->val == 0x02) {
/* Limited discoverable mode */
- hci_cp.num_iac = 2;
+ hci_cp.num_iac = min_t(u8, hdev->num_iac, 2);
hci_cp.iac_lap[0] = 0x00; /* LIAC */
hci_cp.iac_lap[1] = 0x8b;
hci_cp.iac_lap[2] = 0x9e;