From 872274b992839ff64fe560767fe7ee5f942ccdb1 Mon Sep 17 00:00:00 2001 From: Kiran K Date: Fri, 31 Jan 2025 18:30:19 +0530 Subject: [PATCH] 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: Kiran K Fixes: 05c200c8f029 ("Bluetooth: btintel_pcie: Add handshake between driver and firmware") Reported-by: Bjorn Helgaas Closes: https://patchwork.kernel.org/project/bluetooth/patch/20241001104451.626964-1-kiran.k@intel.com/ Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btintel_pcie.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c index 2b79952f3628..091ffe3e1495 100644 --- a/drivers/bluetooth/btintel_pcie.c +++ b/drivers/bluetooth/btintel_pcie.c @@ -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));