Commit 872274b9 authored by Kiran K's avatar Kiran K Committed by Luiz Augusto von Dentz
Browse files

Bluetooth: btintel_pcie: Fix a potential race condition 



On HCI_OP_RESET command, firmware raises alive interrupt. Driver needs
to wait for this before sending other command. This patch fixes the potential
miss of alive interrupt due to which HCI_OP_RESET can timeout.

Expected flow:
If tx command is HCI_OP_RESET,
  1. set data->gp0_received = false
  2. send HCI_OP_RESET
  3. wait for alive interrupt

Actual flow having potential race:
If tx command is HCI_OP_RESET,
 1. send HCI_OP_RESET
   1a. Firmware raises alive interrupt here and in ISR
       data->gp0_received  is set to true
 2. set data->gp0_received = false
 3. wait for alive interrupt

Signed-off-by: default avatarKiran K <kiran.k@intel.com>
Fixes: 05c200c8 ("Bluetooth: btintel_pcie: Add handshake between driver and firmware")
Reported-by: default avatarBjorn Helgaas <helgaas@kernel.org>
Closes: https://patchwork.kernel.org/project/bluetooth/patch/20241001104451.626964-1-kiran.k@intel.com/


Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
parent b4f82f9e

drivers/bluetooth/btintel_pcie.c

+4 −1
Original line number Diff line number Diff line
@@ -1320,6 +1320,10 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev, 
			if (opcode == 0xfc01)

				btintel_pcie_inject_cmd_complete(hdev, opcode);

		}

		/* Firmware raises alive interrupt on HCI_OP_RESET */

		if (opcode == HCI_OP_RESET)

			data->gp0_received = false;



		hdev->stat.cmd_tx++;

		break;

	case HCI_ACLDATA_PKT:
@@ -1357,7 +1361,6 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev, 
			   opcode, btintel_pcie_alivectxt_state2str(old_ctxt),

			   btintel_pcie_alivectxt_state2str(data->alive_intr_ctxt));

		if (opcode == HCI_OP_RESET) {

			data->gp0_received = false;

			ret = wait_event_timeout(data->gp0_wait_q,

						 data->gp0_received,

						 msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT_MS));