[PATCH BlueZ v2] avdtp: wait for L2CAP Disconnect Rsp before CLOSING->IDLE

[PATCH BlueZ v2] avdtp: wait for L2CAP Disconnect Rsp before CLOSING->IDLE

[Pauli Virtanen]

Delay CLOSING->IDLE until remote acknowledges L2CAP channel closure.

It is not explicitly stated in AVDTP v1.3 Sec. 6.13, but some devices
refuse commands sent immediately after L2CAP Disconnect Req, so wait
until Rsp.

Fails:

> ACL Data RX: Handle 6 flags 0x02 dlen 6
      Channel: 64 len 2 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Close (0x08) Response Accept (0x02) type 0x00 label 0 nosp 0
< ACL Data TX: Handle 6 flags 0x00 dlen 12
      L2CAP: Disconnection Request (0x06) ident 16 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 6 flags 0x00 dlen 22
      Channel: 64 len 18 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Set Configuration (0x03) Command (0x00) type 0x00 label 1 nosp 0
        ACP SEID: 7
        INT SEID: 1
        Service Category: Media Transport (0x01)
        Service Category: Media Codec (0x07)
          Media Type: Audio (0x00)
          Media Codec: MPEG-2,4 AAC (0x02)
            Object Type: MPEG-4 AAC LC (0x40)
            Frequency: 44100 (0x100)
            Channels: 2 (0x04)
            Bitrate: 220000bps
            VBR: No
        Service Category: Delay Reporting (0x08)
> ACL Data RX: Handle 6 flags 0x02 dlen 12
      L2CAP: Disconnection Response (0x07) ident 16 len 4
        Destination CID: 65
        Source CID: 65
> ACL Data RX: Handle 6 flags 0x02 dlen 8
      Channel: 64 len 4 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Set Configuration (0x03) Response Reject (0x03) type 0x00 label 1 nosp 0
        Service Category: Reserved (0x29)
        Error code: UNSUPPORTED_CONFIGURATION (0x29)

Works:

> ACL Data RX: Handle 4 flags 0x02 dlen 6
      Channel: 64 len 2 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Close (0x08) Response Accept (0x02) type 0x00 label 12 nosp 0
< ACL Data TX: Handle 4 flags 0x00 dlen 12
      L2CAP: Disconnection Request (0x06) ident 16 len 4
        Destination CID: 65
        Source CID: 65
> ACL Data RX: Handle 4 flags 0x02 dlen 12
      L2CAP: Disconnection Response (0x07) ident 16 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 4 flags 0x00 dlen 22
      Channel: 64 len 18 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Set Configuration (0x03) Command (0x00) type 0x00 label 13 nosp 0
        ACP SEID: 9
        INT SEID: 2
        Service Category: Media Transport (0x01)
        Service Category: Media Codec (0x07)
          Media Type: Audio (0x00)
          Media Codec: MPEG-2,4 AAC (0x02)
            Object Type: MPEG-4 AAC LC (0x40)
            Frequency: 44100 (0x100)
            Channels: 2 (0x04)
            Bitrate: 220000bps
            VBR: No
        Service Category: Delay Reporting (0x08)
> ACL Data RX: Handle 4 flags 0x02 dlen 6
      Channel: 64 len 2 [PSM 25 mode Basic (0x00)] {chan 0}
      AVDTP: Set Configuration (0x03) Response Accept (0x02) type 0x00 label 13 nosp 0

Fixes: https://github.com/bluez/bluez/issues/1471
Fixes: aa118e965b ("a2dp: Don't wait to reconfigure")
---

Notes:
    v2:
    - SHUT_WR is a much simpler way to do it. This leaves dealing with any
      L2CAP timeouts to the kernel.

 profiles/audio/avdtp.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/profiles/audio/avdtp.c b/profiles/audio/avdtp.c
index 30648251f..2f6eaf2ea 100644
--- a/profiles/audio/avdtp.c
+++ b/profiles/audio/avdtp.c
@@ -752,6 +752,8 @@ static void transport_cb(int cond, void *data)
 	struct avdtp_stream *stream = data;
 	struct avdtp_local_sep *sep = stream->lsep;
 
+	DBG("");
+
 	if (stream->close_int && sep->cfm && sep->cfm->close)
 		sep->cfm->close(stream->session, sep, stream, NULL,
 				sep->user_data);
@@ -2922,7 +2924,14 @@ static gboolean avdtp_close_resp(struct avdtp *session,
 {
 	avdtp_stream_set_state(stream, AVDTP_STATE_CLOSING);
 
-	close_stream(stream);
+	/* Delay CLOSING->IDLE until remote acknowledges L2CAP channel closure.
+	 *
+	 * It is not explicitly stated in AVDTP v1.3 Sec. 6.13, but some devices
+	 * refuse commands sent immediately after L2CAP Disconnect Req, so wait
+	 * until Rsp.
+	 */
+	if (stream->io)
+		shutdown(g_io_channel_unix_get_fd(stream->io), SHUT_WR);
 
 	return TRUE;
 }
-- 
2.51.0

RE: [BlueZ,v2] avdtp: wait for L2CAP Disconnect Rsp before CLOSING->IDLE

[bluez.test.bot]

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This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1002167

---Test result---

Test Summary:
CheckPatch                    PENDING   0.27 seconds
GitLint                       PENDING   0.30 seconds
BuildEll                      PASS      19.88 seconds
BluezMake                     PASS      2513.13 seconds
MakeCheck                     PASS      20.40 seconds
MakeDistcheck                 PASS      183.07 seconds
CheckValgrind                 PASS      233.38 seconds
CheckSmatch                   PASS      304.29 seconds
bluezmakeextell               PASS      127.37 seconds
IncrementalBuild              PENDING   0.33 seconds
ScanBuild                     PASS      905.62 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH BlueZ v2] avdtp: wait for L2CAP Disconnect Rsp before CLOSING->IDLE

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluez.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Sun, 14 Sep 2025 15:56:02 +0300 you wrote:
> Delay CLOSING->IDLE until remote acknowledges L2CAP channel closure.
> 
> It is not explicitly stated in AVDTP v1.3 Sec. 6.13, but some devices
> refuse commands sent immediately after L2CAP Disconnect Req, so wait
> until Rsp.
> 
> Fails:
> 
> [...]

Here is the summary with links:
  - [BlueZ,v2] avdtp: wait for L2CAP Disconnect Rsp before CLOSING->IDLE
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=4d7d25b70245

You are awesome, thank you!
-- 
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