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Date:   Wed, 2 Mar 2022 09:59:23 +0000
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From:   Chris Clayton <chris2553@googlemail.com>
Subject: Re: bug kernel 5.17, qualcom and intel adapters, unable to reliably
 connect to bluetooth devices
To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     Chris Murphy <lists@colorremedies.com>,
        Bluetooth <linux-bluetooth@vger.kernel.org>,
        regressions@lists.linux.dev
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Hi Luiz,

Good news...

On 02/03/2022 06:55, Luiz Augusto von Dentz wrote:

<snip>
>>
>> Looks like I was able to reproduce but I still don't know the cause,
>> anyway the symptom is the following:
>>
>> [23412.856410] remove_uuid:2273: hci0: sock 0000000049dcd70a
>> [23412.856467] mgmt_class_complete:2174: hci0: err 0
>> [23412.856470] mgmt_cmd_complete:176: sock 00000000d63e046a
>>
>> It looks like the cmd->sk is wrong/corrupted, what is even more
>> strange is that the socket pointer does seem to match previously
>> connected MGMT clients and after a few attempts with btmgmt> power on
>> it does come back to life, very bizarre...
>>
>> Can you try to enable some kernel debugs before you start bluetoothd:
>>
>> echo "file net/bluetooth/mgmt.c +pfl" > /sys/kernel/debug/dynamic_debug/control
>> echo "file net/bluetooth/mgmt_util.c +pfl" >
>> /sys/kernel/debug/dynamic_debug/control
>>
>> Maybe that should give us a clue what triggers it.
> 
> Here is an attempt to fix the problem:
> 
> https://patchwork.kernel.org/project/bluetooth/patch/20220302064351.225212-1-luiz.dentz@gmail.com/
> 
> Also it probably make more sense to test with the following tree since
> we are using it to push regression fixes:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/
> 

I've cloned bluetooth.git, applied the patch and installed the resultant kernel. I've booted into the kernel eight times
and on each occasion , my bluetooth devices connected successfully. Additionally, I've the latest updates from Linus'
tree into my local clone and applied your patch to that. That too has resulted in a working bluetooth service.

Thanks and well done to you and your colleagues.

For the patch above:

Tested-by: Chris Clayton <chris2553@googlemail.com>

>>>>>>>
>>>>>>> --
>>>>>>> Luiz Augusto von Dentz
>>>>>>
>>>>>>
>>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Luiz Augusto von Dentz
>>>
>>>
>>>
>>> --
>>> Luiz Augusto von Dentz
>>
>>
>>
>> --
>> Luiz Augusto von Dentz
> 
> 
>