Bluetooth: hci_conn: Only do ACL connections sequentially

[ Upstream commit 45340097ce6ea7e875674a5a7d24c95ecbc93ef9 ]

Pretty much all bluetooth chipsets only support paging a single device at
a time, and if they don't reject a secondary "Create Connection" request
while another is still ongoing, they'll most likely serialize those
requests in the firware.

With commit 4c67bc74f016 ("[Bluetooth] Support concurrent connect
requests") we started adding some serialization of our own in case the
adapter returns "Command Disallowed" HCI error.

This commit was using the BT_CONNECT2 state for the serialization, this
state is also used for a few more things (most notably to indicate we're
waiting for an inquiry to cancel) and therefore a bit unreliable. Also
not all BT firwares would respond with "Command Disallowed" on too many
connection requests, some will also respond with "Hardware Failure"
(BCM4378), and others will error out later and send a "Connect Complete"
event with error "Rejected Limited Resources" (Marvell 88W8897).

We can clean things up a bit and also make the serialization more reliable
by using our hci_sync machinery to always do "Create Connection" requests
in a sequential manner.

This is very similar to what we're already doing for establishing LE
connections, and it works well there.

Note that this causes a test failure in mgmt-tester (test "Pair Device
- Power off 1") because the hci_abort_conn_sync() changes the error we
return on timeout of the "Create Connection". We'll fix this on the
mgmt-tester side by adjusting the expected error for the test.

Signed-off-by: Jonas Dreßler <verdre@v0yd.nl>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Stable-dep-of: 227a0cdf4a02 ("Bluetooth: MGMT: Fix not generating command complete for MGMT_OP_DISCONNECT")
Signed-off-by: Sasha Levin <sashal@kernel.org>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 1c427dd2d418..2129d071c372 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -430,6 +430,7 @@ enum {
 #define HCI_NCMD_TIMEOUT	msecs_to_jiffies(4000)	/* 4 seconds */
 #define HCI_ACL_TX_TIMEOUT	msecs_to_jiffies(45000)	/* 45 seconds */
 #define HCI_AUTO_OFF_TIMEOUT	msecs_to_jiffies(2000)	/* 2 seconds */
+#define HCI_ACL_CONN_TIMEOUT	msecs_to_jiffies(20000)	/* 20 seconds */
 #define HCI_LE_CONN_TIMEOUT	msecs_to_jiffies(20000)	/* 20 seconds */
 #define HCI_LE_AUTOCONN_TIMEOUT	msecs_to_jiffies(4000)	/* 4 seconds */
 
diff --git a/include/net/bluetooth/hci_sync.h b/include/net/bluetooth/hci_sync.h
index 4cb048bdcb1e..532230150cc9 100644
--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -140,3 +140,6 @@ int hci_le_terminate_big_sync(struct hci_dev *hdev, u8 handle, u8 reason);
 int hci_le_big_terminate_sync(struct hci_dev *hdev, u8 handle);
 
 int hci_le_pa_terminate_sync(struct hci_dev *hdev, u16 handle);
+
+int hci_acl_create_connection_sync(struct hci_dev *hdev,
+				   struct hci_conn *conn);