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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Wed, 10 Aug 2022 13:04:50 -0700
Message-ID: <CABBYNZ+vRqqCBVTgQJ-UZ+gd2ceFebQF94NDdYcN4Xmyk+GWTA@mail.gmail.com>
Subject: Re: [PATCH v7 2/7] Bluetooth: Add initial implementation of CIS connections
To:     Marek Szyprowski <m.szyprowski@samsung.com>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
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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.

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


-- 
Luiz Augusto von Dentz