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Message-ID: <d41d8b41-c347-47e7-e52b-39d7211c8952@molgen.mpg.de>
Date:   Mon, 7 Feb 2022 14:14:20 +0100
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Subject: Re: Unable to transfer big files to Nokia N9
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To:     Thorsten Leemhuis <regressions@leemhuis.info>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        linux-bluetooth@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>, regressions@lists.linux.dev,
        Takashi Iwai <tiwai@suse.com>
References: <eb6d86eb-d156-d7ac-0965-181719023d51@molgen.mpg.de>
 <CABBYNZLENxvXMCh6XbBSnu0jasV1F0QestEK5v2mnNUpJdw3Vw@mail.gmail.com>
 <cf71bdea-ec22-e4c9-016c-69e94a130607@molgen.mpg.de>
 <a93c0fa7-7b84-6aea-265b-c913e0c84678@molgen.mpg.de>
 <d7206e12-1b99-c3be-84f4-df22af427ef5@molgen.mpg.de>
 <371027df-7f32-edab-208d-d4cdd2202ba6@leemhuis.info>
From:   Paul Menzel <pmenzel@molgen.mpg.de>
In-Reply-To: <371027df-7f32-edab-208d-d4cdd2202ba6@leemhuis.info>
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Dear Thorsten, dear Luiz,


Am 28.01.22 um 11:36 schrieb Thorsten Leemhuis:
> Hi, this is your Linux kernel regression tracker speaking.

Thorsten, thank you for following up on this.

> On 16.01.22 14:27, Paul Menzel wrote:
>> #regzbot introduced: 81be03e026dc0c16dc1c64e088b2a53b73caa895
> 
> thx for getting regzbot involved, much appreciated!
> 
>> Dear Luiz,
>>
>> It turns out there was a regression in Linux 5.16-rc1.
> 
> @bt-maintaners, what's the status here? Paul reported that over ten days
> ago and there wasn't a single reply. Or did the discussion move
> somewhere else?
> 
> @Paul: just wondering, did you give 5.17-rc1 a try? Might be worth a
> shot, if only to confirm the issue is still present.

I just tried with 5.17-rc3, and the issue is still present.


Kind regards,

Paul


>> Am 20.12.21 um 22:31 schrieb Paul Menzel:
>>
>>> Am 01.12.21 um 23:07 schrieb Paul Menzel:
>>>
>>>> Am 01.12.21 um 19:29 schrieb Luiz Augusto von Dentz:
>>>>
>>>>> On Wed, Dec 1, 2021 at 9:39 AM Paul Menzel <pmenzel@molgen.mpg.de>
>>>>> wrote:
>>>>
>>>>>> For the first time, I wanted to transfer a 2 MB PDF file from a Dell
>>>>>> Latitude E7250 with Debian sid/unstable with Linux 5.16-rc1 to a Nokia
>>>>>> N9 (MeeGo/Harmattan). Using the package *bluez-obexd* 5.61-1 and GNOME
>>>>>> 41, the device was found, and paired fine. Then I selected to transfer
>>>>>> the 2 MB file, and after starting for a second, it timed out after the
>>>>>> progress bar moves forward ones and failed.
>>>>>>
>>>>>> The systemd journal contains:
>>>>>>
>>>>>>        obexd[21139]: Transfer(0x56243fe4f790) Error: Timed out
>>>>>> waiting for response
>>>>>>
>>>>>> Testing with a a 5 byte test text file, worked fine. Also testing
>>>>>> with a
>>>>>> Galaly M32, both files were transferred without problems (though
>>>>>> slowly
>>>>>> with 32 KB/s.)
>>>>>>
>>>>>> Trying to connect to the device with bluetoothctl failed for me,
>>>>>> and the
>>>>>> journal contained, it failed.
>>>>>>
>>>>>>        $ bluetoothctl
>>>>>>        Agent registered
>>>>>>        [bluetooth]# connect 40:98:4E:5B:CE:XX
>>>>>>        Attempting to connect to 40:98:4E:5B:CE:XX
>>>>>>        Failed to connect: org.bluez.Error.Failed
>>>>>>
>>>>>>        bluetoothd[21104]: src/service.c:btd_service_connect()
>>>>>> a2dp-source profile connect failed for 40:98:4E:5B:CE:B3: Protocol
>>>>>> not available
>>>>>>
>>>>>> As the Nokia N9 was once pretty popular in the Linux community, I am
>>>>>> pretty sure, it used to work fine in the past, and there is some
>>>>>> regression. It’d be great, if you could give me some hints how to
>>>>>> further debug the issue.
>>>>>
>>>>> We will need some logs, obexd and btmon, if possible.
>>>>
>>>> I only managed to get the btmon trace [1]. I did `sudo modprobe -r
>>>> btusb` and `sudo btmon -w /dev/shm/trace.log`.
>>>>
>>>> Linux messages:
>>>>
>>>>       [29880.100381] calling  btusb_driver_init+0x0/0x1000 [btusb] @
>>>> 28716
>>>>       [29880.239603] usbcore: registered new interface driver btusb
>>>>       [29880.239608] initcall btusb_driver_init+0x0/0x1000 [btusb]
>>>> returned 0 after 135952 usecs
>>>>       [29880.240706] Bluetooth: hci0: unexpected event for opcode 0x0500
>>>>       [29880.241598] Bluetooth: hci0: Legacy ROM 2.5 revision 1.0
>>>> build 3 week 17 2014
>>>>       [29880.241605] Bluetooth: hci0: Intel device is already patched.
>>>> patch num: 32
>>>>
>>>>   From the system journal:
>>>>
>>>>       Dez 01 22:52:19 ersatz obexd[21139]: Transfer(0x56243fe53dd0)
>>>> Error: Timed out waiting for response
>>>
>>> Were you able to see anything in the attached logs? If the obexd logs
>>> are missing, can you please tell how I should capture them?
>>>
>>> I also tested with Ubuntu 20.04 (*linux-image-5.11.0-27-generic*) and
>>> 21.10 (*linux-image-5.13.0-19-generic*) live systems booted from a USB
>>> storage device, and transferring `/usr/bin/systemctl`
>>> (`/lib/systemd/systemd`) with size of 1.8 MB worked fine.
>>>
>>> Could there be a regression in that area? Unfortunately, it’s not easy
>>> for me to do a bisection on the device at hand.
>>>
>>> (Would it be possible to do with QEMU and USB controller and Bluetooth
>>> device passthrough? How can I transfer the file on the command line so
>>> I wouldn’t need to install a desktop environment?)
>>
>> Turns out, that is indeed possible [2], but turned out to be cumbersome,
>> as I hit the regression [3], which seems to have been fixed by commit
>> 95655456e7ce (Bluetooth: btintel: Fix broken LED quirk for legacy ROM
>> devices) merged in the current Linux 5.17 cycle this week.
>>
>> As a work around, I applied a hunk from Takashi’s patch.
>>
>> -       { USB_DEVICE(0x8087, 0x0a2a), .driver_info =
>> BTUSB_INTEL_COMBINED },
>> +       { USB_DEVICE(0x8087, 0x0a2a), .driver_info = BTUSB_INTEL_COMBINED |
>> + BTUSB_INTEL_BROKEN_INITIAL_NCMD },
>>
>> My problem with the Nokia N9 is still present in Linus’ master branch.
>>
>> Then I built a minimal Linux kernel for QEMU, and ran:
>>
>>      qemu-system-x86_64 -cpu host -m 2G -enable-kvm \
>>        -usb -device usb-host,vendorid=0x8087,productid=0x0a2a \
>>        -drive file=/dev/shm/debian-64.img,format=raw,if=virtio \
>>        -net nic -net user,hostfwd=tcp::22223-:22 \
>>        -kernel /dev/shm/bzImage -append "root=/dev/vda1 rw quiet"
>>
>> In the Debian sid/unstable VM, I used
>>
>>      ssh root@localhost -p 22223
>>
>> I once had to pair the VM with the Nokia N9 in bluetoothctl, and then
>> started `/usr/libexec/bluetooth/obexd`, and ran `obexctl`, and connected
>> first with `connect`, and then ran `send /lib/systemd/systemd` to
>> transfer the file. In the problematic cases it stopped/hung after the
>> first progress message.
>>
>>      # obexctl
>>      [NEW] Client /org/bluez/obex
>>      [obex]# connect 40:98:4E:5B:CE:XX
>>      Attempting to connect to 40:98:4E:5B:CE:XX
>>      [NEW] Session /org/bluez/obex/client/session0 [default]
>>      [NEW] ObjectPush /org/bluez/obex/client/session0
>>      Connection successful
>>      [40:98:4E:5B:CE:XX]# send /lib/systemd/systemd
>>      Attempting to send /lib/systemd/systemd to
>> /org/bluez/obex/client/session0
>>      [NEW] Transfer /org/bluez/obex/client/session0/transfer0
>>      Transfer /org/bluez/obex/client/session0/transfer0
>>          Status: queued
>>          Name: systemd
>>          Size: 1841712
>>          Filename: /lib/systemd/systemd
>>          Session: /org/bluez/obex/client/session0
>>      [CHG] Transfer /org/bluez/obex/client/session0/transfer0 Status: active
>>      [CHG] Transfer /org/bluez/obex/client/session0/transfer0
>> Transferred: 32737 (@32KB/s 00:55)
>>      [CHG] Transfer /org/bluez/obex/client/session0/transfer0 Status: error
>>      [DEL] Transfer /org/bluez/obex/client/session0/transfer0
>>
>> Some manual bisection of Linux releases, verified, that the regression
>> was introduced in Linux 5.16-rc1. (Lucky me, I started using Bluetooth
>> with the Nokia with Linux 5.16-rc1.) Then I verified it was introduced
>> by the Bluetooth pull request for Linux 5.16. Then I picked commit
>> 81be03e026dc0c16dc1c64e088b2a53b73caa895 due to the commit message, and
>> bisected from there, and it turns out, that this commit is actually
>> introducing the regression.
>>
>>      $ git bisect good
>>      81be03e026dc0c16dc1c64e088b2a53b73caa895 is the first bad commit
>>      commit 81be03e026dc0c16dc1c64e088b2a53b73caa895
>>      Author: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
>>      Date:   Fri Sep 3 15:27:32 2021 -0700
>>
>>          Bluetooth: RFCOMM: Replace use of memcpy_from_msg with
>> bt_skb_sendmmsg
>>
>>          This makes use of bt_skb_sendmmsg instead using memcpy_from_msg
>> which
>>          is not considered safe to be used when lock_sock is held.
>>
>>          Also make rfcomm_dlc_send handle skb with fragments and queue
>> them all
>>          atomically.
>>
>>          Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
>>          Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
>>
>>       net/bluetooth/rfcomm/core.c | 50
>> ++++++++++++++++++++++++++++++++++++++-------
>>       net/bluetooth/rfcomm/sock.c | 46
>> +++++++++--------------------------------
>>       2 files changed, 53 insertions(+), 43 deletions(-)
>>
>> Unfortunately, the patch does not cleanly revert, so users have to wait
>> until an expert can take a look, and come up with a fix.
>>
>>
>> Kind regards,
>>
>> Paul
>>
>>
>> PS: For the records:
>>
>>      $ git bisect log
>>      # bad: [81be03e026dc0c16dc1c64e088b2a53b73caa895] Bluetooth: RFCOMM:
>> Replace use of memcpy_from_msg with bt_skb_sendmmsg
>>      # good: [49d8a5606428ca0962d09050a5af81461ff90fbb] Bluetooth: fix
>> init and cleanup of sco_conn.timeout_work
>>      git bisect start '81be03e026dc0' 'HEAD^'
>>      # good: [904c139a2517191e48f9cb1bb2d611ae59434009] Bluetooth: Add
>> support for msbc coding format
>>      git bisect good 904c139a2517191e48f9cb1bb2d611ae59434009
>>      # good: [8bba13b1d08d42e2e8308924fa5c1551a7b2b011] Bluetooth:
>> btintel: Fix incorrect out of memory check
>>      git bisect good 8bba13b1d08d42e2e8308924fa5c1551a7b2b011
>>      # good: [38f64f650dc0e44c146ff88d15a7339efa325918] Bluetooth: Add
>> bt_skb_sendmsg helper
>>      git bisect good 38f64f650dc0e44c146ff88d15a7339efa325918
>>      # good: [0771cbb3b97d3c1d68eecd7f00055f599954c34e] Bluetooth: SCO:
>> Replace use of memcpy_from_msg with bt_skb_sendmsg
>>      git bisect good 0771cbb3b97d3c1d68eecd7f00055f599954c34e
>>      # first bad commit: [81be03e026dc0c16dc1c64e088b2a53b73caa895]
>> Bluetooth: RFCOMM: Replace use of memcpy_from_msg with bt_skb_sendmmsg
>>
>>
>> Kind regards,
>>
>> Paul
>>
>>
>>>> [1]: https://owww.molgen.mpg.de/~pmenzel/trace.log.7z
>> [2]:
>> https://lore.kernel.org/linux-bluetooth/5891f0d5-8d51-9da5-7663-718f301490b1@molgen.mpg.de/T/#u
>>
>> [3]:
>> https://lore.kernel.org/linux-bluetooth/20211202162256.31837-1-tiwai@suse.de/
>>
>>
>>