From: João Paulo Rechi Vita jprvita@gmail.com
[ Upstream commit f80c5dad7b6467b884c445ffea45985793b4b2d0 ]
This commit makes the kernel not send the next queued HCI command until a command complete arrives for the last HCI command sent to the controller. This change avoids a problem with some buggy controllers (seen on two SKUs of QCA9377) that send an extra command complete event for the previous command after the kernel had already sent a new HCI command to the controller.
The problem was reproduced when starting an active scanning procedure, where an extra command complete event arrives for the LE_SET_RANDOM_ADDR command. When this happends the kernel ends up not processing the command complete for the following commmand, LE_SET_SCAN_PARAM, and ultimately behaving as if a passive scanning procedure was being performed, when in fact controller is performing an active scanning procedure. This makes it impossible to discover BLE devices as no device found events are sent to userspace.
This problem is reproducible on 100% of the attempts on the affected controllers. The extra command complete event can be seen at timestamp 27.420131 on the btmon logs bellow.
Bluetooth monitor ver 5.50 = Note: Linux version 5.0.0+ (x86_64) 0.352340 = Note: Bluetooth subsystem version 2.22 0.352343 = New Index: 80:C5:F2:8F:87:84 (Primary,USB,hci0) [hci0] 0.352344 = Open Index: 80:C5:F2:8F:87:84 [hci0] 0.352345 = Index Info: 80:C5:F2:8F:87:84 (Qualcomm) [hci0] 0.352346 @ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.352347 @ MGMT Open: btmon (privileged) version 1.14 {0x0002} 0.352366 @ MGMT Open: btmgmt (privileged) version 1.14 {0x0003} 27.302164 @ MGMT Command: Start Discovery (0x0023) plen 1 {0x0003} [hci0] 27.302310 Address type: 0x06 LE Public LE Random < HCI Command: LE Set Random Address (0x08|0x0005) plen 6 #1 [hci0] 27.302496 Address: 15:60:F2:91:B2:24 (Non-Resolvable)
HCI Event: Command Complete (0x0e) plen 4 #2 [hci0] 27.419117
LE Set Random Address (0x08|0x0005) ncmd 1 Status: Success (0x00) < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #3 [hci0] 27.419244 Type: Active (0x01) Interval: 11.250 msec (0x0012) Window: 11.250 msec (0x0012) Own address type: Random (0x01) Filter policy: Accept all advertisement (0x00)
HCI Event: Command Complete (0x0e) plen 4 #4 [hci0] 27.420131
LE Set Random Address (0x08|0x0005) ncmd 1 Status: Success (0x00) < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #5 [hci0] 27.420259 Scanning: Enabled (0x01) Filter duplicates: Enabled (0x01)
HCI Event: Command Complete (0x0e) plen 4 #6 [hci0] 27.420969
LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Success (0x00)
HCI Event: Command Complete (0x0e) plen 4 #7 [hci0] 27.421983
LE Set Scan Enable (0x08|0x000c) ncmd 1 Status: Success (0x00) @ MGMT Event: Command Complete (0x0001) plen 4 {0x0003} [hci0] 27.422059 Start Discovery (0x0023) plen 1 Status: Success (0x00) Address type: 0x06 LE Public LE Random @ MGMT Event: Discovering (0x0013) plen 2 {0x0003} [hci0] 27.422067 Address type: 0x06 LE Public LE Random Discovery: Enabled (0x01) @ MGMT Event: Discovering (0x0013) plen 2 {0x0002} [hci0] 27.422067 Address type: 0x06 LE Public LE Random Discovery: Enabled (0x01) @ MGMT Event: Discovering (0x0013) plen 2 {0x0001} [hci0] 27.422067 Address type: 0x06 LE Public LE Random Discovery: Enabled (0x01)
Signed-off-by: João Paulo Rechi Vita jprvita@endlessm.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/bluetooth/hci.h | 1 + net/bluetooth/hci_core.c | 5 +++++ net/bluetooth/hci_event.c | 12 ++++++++++++ net/bluetooth/hci_request.c | 5 +++++ net/bluetooth/hci_request.h | 1 + 5 files changed, 24 insertions(+)
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index fbba43e9bef5b..9a5330eed7944 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -282,6 +282,7 @@ enum { HCI_FORCE_BREDR_SMP, HCI_FORCE_STATIC_ADDR, HCI_LL_RPA_RESOLUTION, + HCI_CMD_PENDING,
__HCI_NUM_FLAGS, }; diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index d6b2540ba7f8b..f275c99056507 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -4383,6 +4383,9 @@ void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status, return; }
+ /* If we reach this point this event matches the last command sent */ + hci_dev_clear_flag(hdev, HCI_CMD_PENDING); + /* If the command succeeded and there's still more commands in * this request the request is not yet complete. */ @@ -4493,6 +4496,8 @@ static void hci_cmd_work(struct work_struct *work)
hdev->sent_cmd = skb_clone(skb, GFP_KERNEL); if (hdev->sent_cmd) { + if (hci_req_status_pend(hdev)) + hci_dev_set_flag(hdev, HCI_CMD_PENDING); atomic_dec(&hdev->cmd_cnt); hci_send_frame(hdev, skb); if (test_bit(HCI_RESET, &hdev->flags)) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 609fd6871c5ad..8b893baf9bbe2 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3404,6 +3404,12 @@ static void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *skb, hci_req_cmd_complete(hdev, *opcode, *status, req_complete, req_complete_skb);
+ if (hci_dev_test_flag(hdev, HCI_CMD_PENDING)) { + bt_dev_err(hdev, + "unexpected event for opcode 0x%4.4x", *opcode); + return; + } + if (atomic_read(&hdev->cmd_cnt) && !skb_queue_empty(&hdev->cmd_q)) queue_work(hdev->workqueue, &hdev->cmd_work); } @@ -3511,6 +3517,12 @@ static void hci_cmd_status_evt(struct hci_dev *hdev, struct sk_buff *skb, hci_req_cmd_complete(hdev, *opcode, ev->status, req_complete, req_complete_skb);
+ if (hci_dev_test_flag(hdev, HCI_CMD_PENDING)) { + bt_dev_err(hdev, + "unexpected event for opcode 0x%4.4x", *opcode); + return; + } + if (atomic_read(&hdev->cmd_cnt) && !skb_queue_empty(&hdev->cmd_q)) queue_work(hdev->workqueue, &hdev->cmd_work); } diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index ca73d36cc1494..e9a95ed654915 100644 --- a/net/bluetooth/hci_request.c +++ b/net/bluetooth/hci_request.c @@ -46,6 +46,11 @@ void hci_req_purge(struct hci_request *req) skb_queue_purge(&req->cmd_q); }
+bool hci_req_status_pend(struct hci_dev *hdev) +{ + return hdev->req_status == HCI_REQ_PEND; +} + static int req_run(struct hci_request *req, hci_req_complete_t complete, hci_req_complete_skb_t complete_skb) { diff --git a/net/bluetooth/hci_request.h b/net/bluetooth/hci_request.h index 692cc8b133682..55b2050cc9ff0 100644 --- a/net/bluetooth/hci_request.h +++ b/net/bluetooth/hci_request.h @@ -37,6 +37,7 @@ struct hci_request {
void hci_req_init(struct hci_request *req, struct hci_dev *hdev); void hci_req_purge(struct hci_request *req); +bool hci_req_status_pend(struct hci_dev *hdev); int hci_req_run(struct hci_request *req, hci_req_complete_t complete); int hci_req_run_skb(struct hci_request *req, hci_req_complete_skb_t complete); void hci_req_add(struct hci_request *req, u16 opcode, u32 plen,