Bluetooth: btintel_pcie: Reduce driver buffer posting to prevent race condition

Modify the driver to post 3 fewer buffers than the maximum rx buffers
(64) allowed for the firmware. This change mitigates a hardware issue
causing a race condition in the firmware, improving stability and data
handling.

Signed-off-by: Chandrashekar Devegowda <[email protected]>
Signed-off-by: Kiran K <[email protected]>
Fixes: c2b636b ("Bluetooth: btintel_pcie: Add support for PCIe transport")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

Author: devegowdIntel

drivers/bluetooth/btintel_pcie.c

@@ -398,7 +398,11 @@ static int btintel_pcie_start_rx(struct btintel_pcie_data *data)
 	int i, ret;
 	struct rxq *rxq = &data->rxq;
 
-	for (i = 0; i < rxq->count; i++) {
+	/* Post (BTINTEL_PCIE_RX_DESCS_COUNT - 3) buffers to overcome the
+	 * hardware issues leading to race condition at the firmware.
+	 */
+
+	for (i = 0; i < rxq->count - 3; i++) {
 		ret = btintel_pcie_submit_rx(data);
 		if (ret)
 			return ret;