Re: [PATCH v3] bluetooth: hci_qca: Fix qca6390 enable failure after warm reboot

From: Matthias Kaehlcke
Date: Wed May 27 2020 - 12:48:38 EST


Hi Zijun,

On Wed, May 27, 2020 at 10:32:39AM +0800, Zijun Hu wrote:
> Warm reboot can not restore qca6390 controller baudrate
> to default due to lack of controllable BT_EN pin or power
> supply, so fails to download firmware after warm reboot.
>
> Fixed by sending EDL_SOC_RESET VSC to reset controller
> within added device shutdown implementation.
>
> Signed-off-by: Zijun Hu <zijuhu@xxxxxxxxxxxxxx>
> ---
> drivers/bluetooth/hci_qca.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index e4a6823..4b6f8b6 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1975,6 +1975,34 @@ static void qca_serdev_remove(struct serdev_device *serdev)
> hci_uart_unregister_device(&qcadev->serdev_hu);
> }
>
> +static void qca_serdev_shutdown(struct device *dev)
> +{
> + int ret;
> + int timeout = msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS);
> + struct serdev_device *serdev = to_serdev_device(dev);
> + struct qca_serdev *qcadev = serdev_device_get_drvdata(serdev);
> + const u8 ibs_wake_cmd[] = { 0xFD };
> + const u8 edl_reset_soc_cmd[] = { 0x01, 0x00, 0xFC, 0x01, 0x05 };
> +
> + if (qcadev->btsoc_type == QCA_QCA6390) {
> + serdev_device_write_flush(serdev);
> + serdev_device_write_buf(serdev,
> + ibs_wake_cmd, sizeof(ibs_wake_cmd));
> + serdev_device_wait_until_sent(serdev, timeout);

Why no check of the return value of serdev_device_write_buf() here,
does it make sense to continue if sending the wakeup command failed?

Couldn't serdev_device_write() be used instead of the _write_buf() +
_wait_until_sent() combo?

> + usleep_range(8000, 10000);
> +
> + serdev_device_write_flush(serdev);

I suppose the flush is done because _wait_until_sent() could have timed out.
Another reason to use _device_write() (if suitable), since it returns
-ETIMEDOUT in that case?

> + ret = serdev_device_write_buf(serdev,
> + edl_reset_soc_cmd, sizeof(edl_reset_soc_cmd));
> + if (ret < 0) {
> + BT_ERR("QCA send EDL_RESET_REQ error: %d", ret);
> + return;
> + }
> + serdev_device_wait_until_sent(serdev, timeout);
> + usleep_range(8000, 10000);
> + }
> +}
> +
> static int __maybe_unused qca_suspend(struct device *dev)
> {
> struct hci_dev *hdev = container_of(dev, struct hci_dev, dev);
> @@ -2100,6 +2128,7 @@ static struct serdev_device_driver qca_serdev_driver = {
> .name = "hci_uart_qca",
> .of_match_table = of_match_ptr(qca_bluetooth_of_match),
> .acpi_match_table = ACPI_PTR(qca_bluetooth_acpi_match),
> + .shutdown = qca_serdev_shutdown,
> .pm = &qca_pm_ops,
> },
> };
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
>