On 5/28/2020 12:48 AM, Matthias Kaehlcke wrote:
> 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 <[email protected]>
>> ---
>>  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?
> 
i will correct it at v4 patch
> Couldn't serdev_device_write() be used instead of the _write_buf() +
> _wait_until_sent() combo?
> 
i don't think so, serdev_device_write() is not appropriate at here.
serdev_device_write_wakeup() should be used to release completion hold
by serdev_device_write(), however @hci_serdev_client_ops doesn't use
serdev_device_write_wakeup() to implement its write_wakeup operation.
we don't want to touch common hci_serdev.c code.

>> +            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?
>
flush is prefixed at write operation to speed up
shutdown procedure in case of unexpected data injected
during waiting for controller wakeup.
the combo have been used and i just follow it>> +               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
>>

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a 
Linux Foundation Collaborative Project

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