archive mirror
 help / color / mirror / Atom feed
From: Trent Piepho <>
To:, Pauli Virtanen <>,,
Subject: Re: [PATCH v2] Bluetooth: btusb: Add support USB ALT 3 for WBS
Date: Tue, 20 Jul 2021 13:48:29 -0700	[thread overview]
Message-ID: <4778293.GXAFRqVoOG@zen.local> (raw)
In-Reply-To: <>

On Sunday, July 11, 2021 8:33:57 AM PDT Pauli Virtanen wrote:
> pe, 2021-05-14 kello 11:19 +0800, kirjoitti:
> > Because mSBC frames do not need to be aligned to the SCO packet
> > boundary. Using USB ALT 3 let HCI payload >= 60 bytes, let mSBC
> > data satisfy 60 Bytes avoid payload unaligned situation and fixed
> > some headset no voise issue.
> > 
> > USB Alt 3 supported also need HFP support transparent MTU in 72
> > Bytes.

> This change seemed to break msbc audio on some non-realtek adapters I
> have. Tested Pipewire on BCM20702A1 (0b05:17cb), CSR8510A10 (0a12:0001)
> -> no sound output and input appears garbled. Reverting this patch
> makes it work again. Indeed these adapters report SCO mtu=64 which is
> less than 72. On the other hand, with RTL8761BU (0bda:8771) msbc audio
> works fine with this patch out of the box, indeed reading/writing 72
> byte packets to/from the sco socket

When I fixed WBS when previous patches from Intel and Realtek broke it for 
most adapters, I also tested alt 3.  I also found it didn't work for many 

It is annoying that a chipset vendor can not be bothered to do the basic 
testing I am able to do by buying random bt adapters from amazon.  Nor 
respond when their patches, once accepted, cause problems.

      reply	other threads:[~2021-07-20 21:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-14  3:19 [PATCH v2] Bluetooth: btusb: Add support USB ALT 3 for WBS hildawu
2021-05-14  4:21 ` [v2] "
2021-05-20 15:23 ` [PATCH v2] " Marcel Holtmann
2021-07-11 15:33 ` Pauli Virtanen
2021-07-20 20:48   ` Trent Piepho [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4778293.GXAFRqVoOG@zen.local \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).