Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <1a5ec80d-690f-285c-3da8-ccdaf5516d85@pengutronix.de>
Date:   Fri, 24 Jun 2022 14:53:23 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.9.0
Subject: Re: [BUG] BLE device unpairing triggers kernel panic
Content-Language: en-US
To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        "regressions@lists.linux.dev" <regressions@lists.linux.dev>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Tedd Ho-Jeong An <hj.tedd.an@gmail.com>
References: <a1ce1743-e450-6cdb-dfab-56a3e3eb9aed@pengutronix.de>
 <CABBYNZ+z8kBUKGXbZSfb0ynJaTnPQRp0wFDUb12AW1ymbNx1eg@mail.gmail.com>
 <CABBYNZ+zsuggTpaUSPsZKeL=qqvM1=sgMWzdWEqaS_oh6dhY2g@mail.gmail.com>
 <8d5c4724-d511-39b1-21d7-116c91cada45@pengutronix.de>
 <b0cb4fb0-6b89-b9df-9ae6-421ac52b0100@pengutronix.de>
 <CABBYNZ+ubN2rc=zoN_53Pmp6kt3L5UcY3knbtjhhVOjPBpJv4Q@mail.gmail.com>
 <d5654901-6b1f-a1fa-0101-8b52b345af7b@pengutronix.de>
 <CABBYNZ+8dpPBqaQMr-Hz_DJRxT-0ucCjgAJH50FUaN7Sn9H6rA@mail.gmail.com>
 <1d1b76cf-df6f-3935-5cd2-c45ea78f2c33@pengutronix.de>
 <CABBYNZLdy-rndKczoG_WiWXQmacX+vzCbftQKvzJ3B6imtZopw@mail.gmail.com>
From:   Ahmad Fatoum <a.fatoum@pengutronix.de>
In-Reply-To: <CABBYNZLdy-rndKczoG_WiWXQmacX+vzCbftQKvzJ3B6imtZopw@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Tedd, Luiz,

On 21.06.22 20:52, Luiz Augusto von Dentz wrote:
> Hi Ahmad, Tedd,
> 
> On Tue, Jun 21, 2022 at 1:32 AM Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>>
>> Hello Luiz,
>>
>> On 20.06.22 22:18, Luiz Augusto von Dentz wrote:
>>> On Mon, Jun 20, 2022 at 3:06 AM Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>>>> Disconnect of connection #1 being processed after new connection #2
>>>> concluded sounds wrong. Would I be able to reconnect
>>>> afterwards or would all connections, but the first, be directly
>>>> disconnected...?
>>>
>>> That depends on the order you have queued the commands, it will be
>>> processed in the exact order it is received, that why I said it is
>>> single queue design, and it is done like that to prevent messing up
>>> with states since we know the exact order the commands will be sent.
>>>
>>>>> otherwise we need a
>>>>> different queue to handle command that abort/cancel other already in
>>>>> the queue.
>>>>
>>>> Is the revert an acceptable interim solution or are there issues
>>>> I am missing?
>>>
>>> Afaik there were problem with concurrent connections request, so what
>>> would really help us here is to have some tests to emulate this
>>> scenario with our CI, in the meantime please check if the following
>>> fixes your problem:
>>>
>>> https://gist.github.com/Vudentz/b4fff292c7f4ad55ca3299fd5ab797ae
>>
>> Doesn't help unfortunately. First pairing works as before.
>> Second still fails:
>>
>>   Bluetooth: hci0: Opcode 0x200d failed: -110
>>   Bluetooth: hci0: request failed to create LE connection: err -110
> 
> Can we try to add a test in mgmt-tester to reproduce the error above?

I am not familiar with mgmt-tester. What information do you
need to reproduce? In the meantime, can we revert the commit?
I understand that this may break other uses, but I believe
previously working stuff should have precedence..

Cheers,
Ahmad

> 
>> Cheers,
>> Ahmad
>>
>>>
>>>> Cheers,
>>>> Ahmad
>>>>
>>>>>
>>>>>> We've been deploying the revert for a while now and I just posted
>>>>>> it to the mailing list[1]. There have been other reports
>>>>>> of this issue with different hardware too and fixing sent_cmd
>>>>>> would likely be too complicated/time intensive for me.
>>>>>>
>>>>>> I am happy to test future patches that fix this properly though.
>>>>>>
>>>>>> [1]: https://lore.kernel.org/linux-bluetooth/20220616092418.738877-1-a.fatoum@pengutronix.de/T/#t
>>>>>>
>>>>>> Cheers,
>>>>>> Ahmad
>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Ahmad
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Pengutronix e.K.                           |                             |
>>>>>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>>>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>>>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Pengutronix e.K.                           |                             |
>>>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>
>>>
>>>
>>
>>
>> --
>> Pengutronix e.K.                           |                             |
>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 
> 
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |