Date:   Tue, 8 Feb 2022 08:49:40 +0100
From:   Paul Menzel <pmenzel@...gen.mpg.de>
To:     Thorsten Leemhuis <regressions@...mhuis.info>,
        Luiz Augusto von Dentz <luiz.dentz@...il.com>
Cc:     Marcel Holtmann <marcel@...tmann.org>,
        Johan Hedberg <johan.hedberg@...il.com>,
        linux-bluetooth@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>, regressions@...ts.linux.dev,
        Takashi Iwai <tiwai@...e.com>
Subject: Re: Unable to transfer big files to Nokia N9

Dear Thorsten, dear Luiz,


Am 07.02.22 um 14:14 schrieb Paul Menzel:

> 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.

Merging 4840aa67576b (Bluetooth: hci_core: Fix leaking sent_cmd skb) from

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git

into Linux 5.17-rc3, the resulting Linux kernel also has the problem.


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@...gen.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@...alhost -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@...el.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@...el.com>
>>>          Signed-off-by: Marcel Holtmann <marcel@...tmann.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/

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