Re: Problem with re-loading hci_uart.ko on RPi3

[Stefan Wahren <stefan.wahren@i2se.com>]

Hi Marcel,

Am 26.02.2018 um 09:13 schrieb Marcel Holtmann:
> Hi Stefan,
>
>>>>>> After enabling bluetooth scanning i will see these error messages periodically:
>>>>>>
>>>>>> [  815.939839] Bluetooth: hci0: last event is not cmd complete (0x0f)
>>>>>> [  831.302476] Bluetooth: hci0: last event is not cmd complete (0x0f)
>>>>>> [  847.303953] Bluetooth: hci0: last event is not cmd complete (0x0f)
>>>>>> [  863.305284] Bluetooth: hci0: last event is not cmd complete (0x0f)
>>>>>> [  879.306838] Bluetooth: hci0: last event is not cmd complete (0x0f)
>>>>> I really need to hook up the error messages into the btmon output since then we can trace where these are coming from. Anyway, can you btmon -w trace.log from before loading the module and this error showing up.
>>>> I attached the log. According to dmesg this error happend only once during the trace.
>>> I will add bt_dev_err tracing to be include in btmon and that way we can figure out where that error happens. Or do you have a trace.log and dmesg -T where we can correlate it based on time.
>> Please look at this attachment and the following output (issue appears every 16 seconds after enabling scanning even if i use a baudrate of 115200):
>>
>> 2018-02-23T14:12:52,454443+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:13:08,454601+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:13:24,453167+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:13:40,453414+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:13:56,453859+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:14:12,453864+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:14:28,453966+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:14:44,455381+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:15:00,452972+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:15:16,453733+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:15:32,453318+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:15:48,453495+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:16:04,452430+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:16:20,452531+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:16:36,452813+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>> 2018-02-23T14:16:52,453043+0100 Bluetooth: hci0: last event is not cmd complete (0x0f)
>>
>> I also noticed a different issue (only tested 4.15 yet), sometimes if i try to unload "modprobe -r hci_uart" the command blocks forever. There is no crash just the command hangs.
> so it seems that this matched up to the set scan enable command.
Hm, i only enabled the scanning once. Does bluetoothctl send this 
command periodically every 16 seconds?
>
> < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2        #415 [hci0] 2018-02-23 14:12:52.478963
>          Scanning: Disabled (0x00)
>          Filter duplicates: Disabled (0x00)
>> HCI Event: Command Complete (0x0e) plen 4                   #416 [hci0] 2018-02-23 14:12:52.483769
>        LE Set Scan Enable (0x08|0x000c) ncmd 1
>          Status: Success (0x00)
>
> Does this happen with all baud rates or just with 115200?

I've seen this at 115200 and 2000000 baud.

Stefan