From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balakrishna Godavarthi Subject: [PATCH v5 3/5] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990 Date: Thu, 20 Dec 2018 20:16:37 +0530 Message-ID: <20181220144639.15928-4-bgodavar@codeaurora.org> References: <20181220144639.15928-1-bgodavar@codeaurora.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181220144639.15928-1-bgodavar@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: marcel@holtmann.org, johan.hedberg@gmail.com, johan@kernel.org Cc: mka@chromium.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, Balakrishna Godavarthi List-Id: linux-arm-msm@vger.kernel.org During initalization of wcn3990, we observed UART is reading some stray bytes on the Rx line. This is logging Frame reassembly errors on the serial console. This could be because of tristate of Tx line of wcn3990 during boot up. [ 176.929612] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84) [ 176.945734] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84) [ 176.953298] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84) [ 177.010660] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84) [ 177.067633] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84) Now we enable a flag during bootup to stop executing proto receive function and clear it back once the initialization is done. Signed-off-by: Balakrishna Godavarthi Tested-by: Matthias Kaehlcke --- drivers/bluetooth/hci_qca.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index 1680ead6cc3d..52de0b5a0620 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -56,6 +56,7 @@ /* Controller states */ #define STATE_IN_BAND_SLEEP_ENABLED 1 +#define STATE_DISCARD_RX 2 #define IBS_WAKE_RETRANS_TIMEOUT_MS 100 #define IBS_TX_IDLE_TIMEOUT_MS 2000 @@ -511,6 +512,7 @@ static int qca_open(struct hci_uart *hu) } else { hu->init_speed = qcadev->init_speed; hu->oper_speed = qcadev->oper_speed; + set_bit(STATE_DISCARD_RX, &qca->flags); ret = qca_power_setup(hu, true); if (ret) { destroy_workqueue(qca->workqueue); @@ -903,6 +905,13 @@ static int qca_recv(struct hci_uart *hu, const void *data, int count) if (!test_bit(HCI_UART_REGISTERED, &hu->flags)) return -EUNATCH; + /* We discard Rx data received while device is in booting + * stage, This is because of BT chip Tx line is in tristate. + * Due to this we read some garbage data on UART Rx. + */ + if (test_bit(STATE_DISCARD_RX, &qca->flags)) + return 0; + qca->rx_skb = h4_recv_buf(hu->hdev, qca->rx_skb, data, count, qca_recv_pkts, ARRAY_SIZE(qca_recv_pkts)); if (IS_ERR(qca->rx_skb)) { @@ -1194,6 +1203,7 @@ static int qca_setup(struct hci_uart *hu) if (ret) return ret; + clear_bit(STATE_DISCARD_RX, &qca->flags); ret = qca_read_soc_version(hdev, &soc_ver); if (ret) return ret; @@ -1270,6 +1280,12 @@ static const struct qca_vreg_data qca_soc_data = { static void qca_power_shutdown(struct hci_uart *hu) { + struct qca_data *qca = hu->priv; + + /* From this point we go into power off state. But serial port is + * still open, discard all the garbage data received on the Rx line. + */ + set_bit(STATE_DISCARD_RX, &qca->flags); serdev_device_write_flush(hu->serdev); host_set_baudrate(hu, 2400); qca_send_power_pulse(hu, QCA_WCN3990_POWEROFF_PULSE); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project