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Date:   Fri, 12 Aug 2022 14:33:48 +0200
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Subject: Re: [PATCH v7 2/7] Bluetooth: Add initial implementation of CIS
 connections
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To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
From:   Marek Szyprowski <m.szyprowski@samsung.com>
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Hi Luiz,

On 10.08.2022 22:04, Luiz Augusto von Dentz wrote:
> Hi Marek,
>
> On Wed, Aug 10, 2022 at 7:18 AM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>> Hi Luiz,
>>
>> On 09.08.2022 21:24, Luiz Augusto von Dentz wrote:
>>> On Tue, Aug 9, 2022 at 1:55 AM Marek Szyprowski
>>> <m.szyprowski@samsung.com>  wrote:
>>>> On 12.07.2022 01:35, Luiz Augusto von Dentz wrote:
>>>>> From: Luiz Augusto von Dentz<luiz.von.dentz@intel.com>
>>>>>
>>>>> This adds the initial implementation of CIS connections and introduces
>>>>> the ISO packets/links.
>>>>>
>>>>> == Central: Set CIG Parameters, create a CIS and Setup Data Path ==
>>>>>
>>>>>> tools/isotest -s <address>
>>>>> < HCI Command: LE Extended Create... (0x08|0x0043) plen 26
>>>>> ...
>>>>>> HCI Event: Command Status (0x0f) plen 4
>>>>>          LE Extended Create Connection (0x08|0x0043) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>> HCI Event: LE Meta Event (0x3e) plen 31
>>>>>          LE Enhanced Connection Complete (0x0a)
>>>>>          ...
>>>>> < HCI Command: LE Create Connected... (0x08|0x0064) plen 5
>>>>> ...
>>>>>> HCI Event: Command Status (0x0f) plen 4
>>>>>          LE Create Connected Isochronous Stream (0x08|0x0064) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>> HCI Event: LE Meta Event (0x3e) plen 29
>>>>>          LE Connected Isochronous Stream Established (0x19)
>>>>>          ...
>>>>> < HCI Command: LE Setup Isochronou.. (0x08|0x006e) plen 13
>>>>> ...
>>>>>> HCI Event: Command Complete (0x0e) plen 6
>>>>>          LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>            Handle: 257
>>>>> < HCI Command: LE Setup Isochronou.. (0x08|0x006e) plen 13
>>>>> ...
>>>>>> HCI Event: Command Complete (0x0e) plen 6
>>>>>          LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>            Handle: 257
>>>>>
>>>>> == Peripheral: Accept CIS and Setup Data Path ==
>>>>>
>>>>>> tools/isotest -d
>>>>>     HCI Event: LE Meta Event (0x3e) plen 7
>>>>>          LE Connected Isochronous Stream Request (0x1a)
>>>>> ...
>>>>> < HCI Command: LE Accept Co.. (0x08|0x0066) plen 2
>>>>> ...
>>>>>> HCI Event: LE Meta Event (0x3e) plen 29
>>>>>          LE Connected Isochronous Stream Established (0x19)
>>>>> ...
>>>>> < HCI Command: LE Setup Is.. (0x08|0x006e) plen 13
>>>>> ...
>>>>>> HCI Event: Command Complete (0x0e) plen 6
>>>>>          LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>            Handle: 257
>>>>> < HCI Command: LE Setup Is.. (0x08|0x006e) plen 13
>>>>> ...
>>>>>> HCI Event: Command Complete (0x0e) plen 6
>>>>>          LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
>>>>>            Status: Success (0x00)
>>>>>            Handle: 257
>>>>>
>>>>> Signed-off-by: Luiz Augusto von Dentz<luiz.von.dentz@intel.com>
>>>> This patch landed recently in linux-next as commit 26afbd826ee3
>>>> ("Bluetooth: Add initial implementation of CIS connections").
>>>> Unfortunately it causes a regression on my test systems. On almost all
>>>> I've observed that calling a simple 'hcitool scan' command in a shell
>>>> fails in an unexpected way:
>>>>
>>>> $ hcitool scan
>>>> *** stack smashing detected ***: <unknown> terminated
>>>> Aborted
>>> Not really sure how it would be related to ISO changes though, have
>>> you even enabled ISO sockets UUID? Perhaps check if there is something
>>> on dmesg indicating what is going on since I tried here and that
>>> doesn't seem to cause any problem:
>>>
>>> tools/hcitool scan
>>> Scanning ...
>>>
>>> Perhaps it is a combination of using old userspace tools with new
>>> kernel, but then again these changes should affect something like
>>> hcitool.
>> Indeed my userspace is old, but still, the kernel changes shouldn't make
>> it to crash. I didn't change anything in userspace since ages, so I
>> assume that ISO sockets UUIDs are not enabled. Maybe it is somehow
>> architecture related or specific? It looks that only ARM 32bit userspace
>> apps crashes. I've just checked 64bit userspace on ARM64 (RPi4) and it
>> works fine with that commit.
> That would be the first time it happens to me that a change in kernel
> would crash the userspace in such odd fashion, btw perhaps run with
> valgrind so it generates a backtrace of where it would be crashing,
> well if that is reproducible with valgrind.

Well, its not that easy. I've checked and Debian doesn't provide a 
valgrind package for the buster/armel arch, which I use on my test 
systems (for some historical reasons). Building everything from the 
source will take some time, though. I will try to do this after getting 
back from my holidays after 24th Aug.


Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland