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Bluetooth: btintel_pcie: Fix a potential race condition

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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 <kiran.k@intel.com>
Fixes: 05c200c8f0 ("Bluetooth: btintel_pcie: Add handshake between driver and firmware")
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Closes: https://patchwork.kernel.org/project/bluetooth/patch/20241001104451.626964-1-kiran.k@intel.com/
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Kiran K 2025-01-31 18:30:19 +05:30 • committed by Luiz Augusto von Dentz
parent b4f82f9ed4
commit 872274b992
1 changed files with 4 additions and 1 deletions
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5
drivers/bluetooth/btintel_pcie.c
View file

@ -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));