> ________________________________________ > From: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> > Sent: Thursday, September 11, 2025 17:52 > To: Per Waago (pwaago) > Cc: Pauli Virtanen; linux-bluetooth@xxxxxxxxxxxxxxx > Subject: Re: [PATCH BlueZ] audio: Add support for specific error codes for A2DP configuration > > Hi Per, > > On Thu, Sep 11, 2025 at 11:12 AM Per Waago (pwaago) <pwaago@xxxxxxxxx> wrote: > > > > Hi Luiz, thanks for reviewing. > > > > > From: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> > > > Sent: Thursday, September 11, 2025 16:43 > > > To: Per Waago (pwaago); Pauli Virtanen > > > Cc: linux-bluetooth@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH BlueZ] audio: Add support for specific error codes for A2DP > configuration > > > > > > Hi Per, > > > > > > On Thu, Sep 11, 2025 at 9:56 AM Per Waagø <pwaago@xxxxxxxxx> wrote: > > > > > > > > The A2DP specification defines error codes that shall be used if > > > > the codec capabilities contain improper settings. This change allows > > > > clients to trigger the sending of these specific error codes by > > > > returning the corresponding error messages from > > > > MediaEndpoint1.SetConfiguration. > > > > > > > > This update is fully backwards compatible: clients passing other error > > > > messages will continue to receive the default error code as before. On > > > > older BlueZ versions, these new errors will also result in the default > > > > error code, enabling clients to implement support for the new errors > > > > without breaking compatibility. > > > > > > While I can see the value for debugging I doubt we could do any > > > handling of these errors, so the result would be the same regardless > > > of what error is sent back it is not recoverable. > > > > > > > The main motivation for adding them is to be able to pass the > > mandatory qualification tests, which now checks the errors codes > > returned from SetConfiguration in detail. I don't think they are very > > useful otherwise. > > > > The errors are specified in table 5.5 in the A2DP spec: > > > https://www.bluetooth.com/specifications/specs/html/?src=a2dp_v1-4-1_1752513648/A2DP_v1.4.1/o> ut/en/index-en.html#UUID-0ba19ee9-7277-1068-d2dc-b9e638cca568_Table_5.5 > > > > I included all of them for completeness. In that table, it is also stated > > which codecs they apply to. Some are SBC-specific, some apply to all codecs or > > other codecs. > > Ok this is very annoying if PTS suddenly adds a new test case that > checks error codes that otherwise are only useful for debugging. I'd > say that it probably needs a configuration entry to skip these tests, > btw this seems to be introduced in 1.4.1: > > https://www.bluetooth.com/specifications/specs/html/?src=a2dp_v1-4-1_1752513648/A2DP_v1.4.1/o> ut/en/index-en.html#UUID-05a1c924-2070-eb38-c2cc-a9ffa178bdb9 > > BlueZ SDP record is still 1.4 (a2dp_ver = 0x0104), it seems 1.4.1 is > an errata only change but that introduces new error codes which is > really intrusive to say the least.really intrusive to say the least. I have tried to read the specs in some more detail now. It seems the error codes themselves have been there all the time. The errata that was incorporated in 1.4.1 actually eases the requirements a bit, so the spec now says that these error codes shall be returned if error codes from GAVDP or AVDTP aren't used. So the way I interpret it, returning AVDTP_UNSUPPORTED_CONFIGURAION could be ok according to 1.4.1.
